Discovery signal measurement timing configuration for scells in asynchronous networks

ABSTRACT

Systems and methods relating to Discovery Signal Measurement Timing Configuration (DMTC) are disclosed. In some embodiments, a method of operation of a radio access node in a cellular communications network comprises sending, to a wireless device, a DMTC for one of a group consisting of: (a) a Secondary Cell (SCell) configured for the wireless device such that the DMTC is a specific DMTC for the SCell and (b) a frequency on which one or more asynchronous cells are operating, an asynchronous cell being a cell that is unsynchronized with a Primary Cell (PCell) of the wireless device. A DMTC configuration that is specific to a SCell provides improved measurement performance on the SCell because, e.g., the DMTC configuration can be specifically tailored to that SCell. A DMTC configuration for a frequency on which one or more asynchronous cells are operating provides improved measurement performance on that carrier.

RELATED APPLICATIONS

This application claims the benefit of provisional patent applicationSer. No. 62/347,543, filed Jun. 8, 2016, the disclosure of which ishereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The disclosed subject matter relates generally to telecommunications andmore particularly to Discovery Signal Measurement Timing Configuration(DMTC) for Secondary Cells (SCells) in asynchronous networks.

BACKGROUND

The Third Generation Partnership Project (3GPP) initiative “LicenseAssisted Access” (LAA) intends to allow Long Term Evolution (LTE)equipment to also operate in the unlicensed radio spectrum such as the 5Gigahertz (GHz) band. The unlicensed spectrum is used as a complement tothe licensed spectrum. Accordingly, devices connect in the licensedspectrum to a Primary Cell (PCell) and use Carrier Aggregation (CA) tobenefit from additional transmission capacity in the unlicensed spectrumby connecting to one or more Secondary Cells (SCells) operating in theunlicensed spectrum. To reduce the changes required for aggregatinglicensed and unlicensed spectrum, the LTE frame timing in the PCell issimultaneously used in the SCell(s) (i.e., the PCell and the SCells aresynchronized). In addition to LAA operation, it should be possible torun LTE fully on the unlicensed band without the support from thelicensed band. This is referred to as LTE in the Unlicensed Band (LTE-U)Standalone or MulteFire.

Regulatory requirements, however, may not permit transmissions in theunlicensed spectrum without prior channel sensing. Because theunlicensed spectrum must be shared with other radios of similar ordissimilar wireless technologies, a so called Listen-Before-Talk (LBT)scheme needs to be applied. LBT is also referred to as a Clear ChannelAssessment (CCA). Today, the unlicensed 5 GHz spectrum is mainly used byequipment implementing the IEEE 802.11 Wireless Local Area Network(WLAN) standard. This standard is known under its marketing brand“Wi-Fi.”

The LBT procedure leads to uncertainty at the enhanced or evolved Node B(eNB) regarding whether or not the eNB will be able to transmit adownlink subframe(s). This leads to a corresponding uncertainty at theUser Equipment device (UE) as to whether or not the UE actually has asubframe to decode. An analogous uncertainty exists in the uplinkdirection where the eNB is uncertain as to whether or not the UEsscheduled on the SCell are actually transmitted.

1 LTE

LTE uses Orthogonal Frequency Division Multiplexing (OFDM) in thedownlink and Discrete Fourier Transform (DFT)-spread OFDM (also referredto as single-carrier Frequency Division Multiple Access (FDMA)) in theuplink. The basic LTE downlink physical resource can thus be seen as atime-frequency grid as illustrated in FIG. 1, where each resourceelement corresponds to one OFDM subcarrier during one OFDM symbolinterval. The uplink subframe has the same subcarrier spacing as thedownlink, and the same number of Single Carrier FDMA (SC-FDMA) symbolsin the time domain as OFDM symbols in the downlink.

In the time domain, LTE downlink transmissions are organized into 10millisecond (ms) radio frames, where each radio frame consists of tenequally-sized subframes of length T_(subframe)=1 ms as shown in FIG. 2.For normal cyclic prefix, one subframe consists of 14 OFDM symbols. Theduration of each symbol is approximately 71.4 microseconds (μs).

Furthermore, the resource allocation in LTE is typically described interms of resource blocks, where a resource block corresponds to one slot(0.5 ms) in the time domain and 12 contiguous subcarriers in thefrequency domain. A pair of two adjacent resource blocks in the timedirection (1.0 ms) is known as a resource block pair. Resource blocksare numbered in the frequency domain, starting with 0 from one end ofthe system bandwidth.

Downlink transmissions are dynamically scheduled, i.e., in each subframethe base station transmits control information about which terminalsdata is transmitted to and upon which resource blocks the data istransmitted, in the current downlink subframe. This control signaling istypically transmitted in the first 1, 2, 3, or 4 OFDM symbols in eachsubframe and the number n=1, 2, 3, or 4 is known as the Control FormatIndicator (CFI). The downlink subframe also contains common referencesymbols, which are known to the receiver and used for coherentdemodulation of, e.g., the control information. A downlink system withCFI=3 OFDM symbols as control is illustrated in FIG. 3.

From LTE Release (Rel) 11 onwards, the above described resourceassignments can also be scheduled on the enhanced Physical DownlinkControl Channel (ePDCCH). For Rel-8 to Rel-10, only Physical DownlinkControl Channel (PDCCH) is available.

The reference symbols shown in FIG. 3 are the Cell-Specific ReferenceSymbols (CRSs). The CRSs are used to support multiple functionsincluding fine time and frequency synchronization and channel estimationfor certain transmission modes.

1.1 PDCCH and ePDCCH

The PDCCH/ePDCCH is used to carry Downlink Control Information (DCI)such as scheduling decisions and power control commands. Morespecifically, the DCI includes the following:

-   -   Downlink scheduling assignments, including Physical Downlink        Shared Channel (PDSCH) resource indication, transport format,        Hybrid Automatic Repeat Request (HARQ) information, and control        information related to spatial multiplexing (if applicable). A        downlink scheduling assignment also includes a command for power        control of the Physical Uplink Control Channel (PUCCH) used for        transmission of HARQ acknowledgements in response to downlink        scheduling assignments.    -   Uplink scheduling grants, including Physical Uplink Shared        Channel (PUSCH) resource indication, transport format, and        HARQ-related information. An uplink scheduling grant also        includes a command for power control of the PUSCH.    -   Power control commands for a set of terminals as a complement to        the commands included in the scheduling assignments/grants.        One PDCCH/ePDCCH carries one DCI message containing one of the        groups of information listed above. As multiple terminals can be        scheduled simultaneously, and each terminal can be scheduled on        both downlink and uplink simultaneously, there must be a        possibility to transmit multiple scheduling messages within each        subframe. Each scheduling message is transmitted on separate        PDCCH/ePDCCH resources, and consequently there are typically        multiple simultaneous PDCCH/ePDCCH transmissions within each        subframe in each cell. Furthermore, to support different radio        channel conditions, link adaptation can be used, where the code        rate of the PDCCH/ePDCCH is selected by adapting the resource        usage for the PDCCH/ePDCCH to match the radio channel        conditions.

A discussion of the start symbol for PDSCH and ePDCCH within thesubframe is now provided. The OFDM symbols in the first slot arenumbered from 0 to 6. For transmissions modes 1-9, the starting OFDMsymbol in the first slot of the subframe for ePDCCH can be configured byhigher layer signaling and the same is used for the correspondingscheduled PDSCH. Both sets have the same ePDCCH starting symbol forthese transmission modes. If not configured by higher layers, the startsymbol for both PDSCH and ePDCCH is given by the CFI value signaled inPhysical Control Format Indicator Channel (PCFICH).

Multiple OFDM starting symbol candidates can be achieved by configuringthe UE in transmission mode 10 and having multiple ePDCCH physicalresource block configuration sets. The starting OFDM symbol in the firstslot in a subframe for ePDCCH can be configured independently for eachePDCCH set by higher layers to be a value from {1,2,3,4}. If a set isnot higher layer configured to have a fixed start symbol, then theePDCCH start symbol for this set follows the CFI value received inPCFICH.

1.2 CA

The LTE Rel-10 standard supports bandwidths larger than 20 Megahertz(MHz). One important requirement on LTE Rel-10 is to assure backwardcompatibility with LTE Rel-8. This should also include spectrumcompatibility. That would imply that an LTE Rel-10 carrier, wider than20 MHz, should appear as a number of LTE carriers to an LTE Rel-8terminal. Each such carrier can be referred to as a Component Carrier(CC). In particular, for early LTE Rel-10 deployments, it can beexpected that there will be a smaller number of LTE Rel-10-capableterminals compared to many LTE legacy terminals. Therefore, it isnecessary to assure an efficient use of a wide carrier also for legacyterminals, i.e. that it is possible to implement carriers where legacyterminals can be scheduled in all parts of the wideband LTE Rel-10carrier. One way to obtain this would be by means of CA. CA implies thatan LTE Rel-10 terminal can receive multiple CCs, where the CCs have, orat least have the possibility to have, the same structure as an LTERel-8 carrier. CA is illustrated in FIG. 4. A CA-capable UE is assigneda PCell that is always activated, and one or more SCells that may beactivated or deactivated dynamically.

The number of aggregated CCs as well as the bandwidth of the individualCCs may be different for uplink and downlink. A symmetric configurationrefers to the case where the number of CCs in downlink is the same asthe number of CCs in the uplink whereas an asymmetric configurationrefers to the case where the number of CCs in the downlink is differentthan the number of CCs in the uplink. It is important to note that thenumber of CCs configured in a cell may be different from the number ofCCs seen by a terminal. A terminal may, for example, support moredownlink CCs than uplink CCs, even though the cell is configured withthe same number of uplink and downlink CCs.

In addition, a key feature of CA is the ability to perform cross-carrierscheduling. This mechanism allows a (e)PDCCH on one CC to schedule datatransmissions on another CC by means of a 3-bit Carrier Indicator Field(CIF) inserted at the beginning of the (e)PDCCH messages. For datatransmissions on a given CC, a UE expects to receive scheduling messageson the (e)PDCCH on just one CC—either the same CC or a different CC viacross-carrier scheduling. This mapping from (e)PDCCH to PDSCH isconfigured semi-statically.

1.3 LTE Measurements

The UE performs periodic cell search and Reference Signal Received Power(RSRP) and Reference Signal Received Quality (RSRQ) measurements inRadio Resource Control (RRC) Connected mode. The UE is responsible fordetecting new neighbor cells, and for tracking and monitoring alreadydetected cells. The detected cells and the associated measurement valuesare reported to the network. Reports to the network can be configured tobe periodic or aperiodic based a particular event.

1.4 Rel-12 LTE Discovery Reference Signal (DRS)

To share the channel in the unlicensed spectrum, the cell cannot occupythe channel indefinitely. One of the existing mechanisms forinterference avoidance and coordination among small cells is the SCellON/OFF feature. In Rel-12 LTE, discovery signals were introduced toprovide enhanced support for SCell ON/OFF operations. Specifically,these signals were introduced to handle potentially severe interferencesituations, particularly on the synchronization signals, resulting fromdense deployment as well as to reduce UE inter-frequency measurementcomplexity.

The discovery signals in a DRS occasion are comprised of the PrimarySynchronization Signal (PSS), the Secondary Synchronization Signal(SSS), CRS, and, when configured, the Channel State InformationReference Signals (CSI-RS). The PSS and SSS are used for coarsesynchronization, when needed, and for cell identification. The CRS isused for fine time and frequency estimation and tracking and may also beused for cell validation, i.e., to confirm the cell Identity (ID)detected from the PSS and SSS. The CSI-RS is another signal that can beused in dense deployments for cell or transmission point identification.FIG. 5 shows the presence of these signals in a DRS occasion of lengthequal to two subframes and also shows the transmission of the signalsover two different cells or transmission points.

The DRS occasion corresponding to transmissions from a particular cellmay range in duration from one to five subframes for Frequency DivisionDuplexing (FDD) and two to five subframes for Time Division Duplexing(TDD). The subframe in which the SSS occurs marks the starting subframeof the DRS occasion. This subframe is either subframe 0 or subframe 5 inboth FDD and TDD. In TDD, the PSS appears in subframe 1 and subframe 6while in FDD the PSS appears in the same subframe as the SSS. The CRSsare transmitted in all downlink subframes and the Downlink Part of theSpecial Subframe (DwPTS) regions of special subframes.

The discovery signals should be useable by the UE for performing cellidentification as well as RSRP and RSRQ measurements. The RSRPmeasurement definition based on discovery signals is the same as inprior releases of LTE. The Received Signal Strength Indicator (RSSI)measurement is defined as an average over all OFDM symbols in thedownlink parts of the measured subframes within a DRS occasion. The RSRQis then defined as DRSRQ=N×DRSRP/DRSSI, where N is the number ofphysical resource blocks used in performing the measurement, DRSRP isthe RSRP measurement based on the discovery signals, and DRSSI is theRSSI measured over the DRS occasion.

In LTE Rel-12, RSRP measurements based on the CRS and CSI-RS in the DRSoccasions and RSRQ measurements based on the CRS in the DRS occasionshave been defined. As stated earlier, discovery signals can be used in asmall cell deployment where the cells are being turned off and on or ina general deployment where the on/off feature is not being used. Forinstance, discovery signals could be used to make RSRP measurements ondifferent CSI-RS configurations in the DRS occasion being used within acell, which enables the detection of different transmission points in ashared cell.

When measurements are made on the CSI-RS in a DRS occasion, the UErestricts its measurements to a list of candidates sent to the UE by thenetwork via RRC signaling. Each candidate in this list contains aPhysical Cell Identity (PCID), a Virtual Cell Identity (VCID), and asubframe offset indicating the duration, in number of subframes, betweenthe subframe where the UE receives the CSI-RS and the subframe carryingthe SSS. This information allows the UE to limit its search. The UEcorrelates to the received signal candidates indicated by the RRC signaland reports back any CSI-RS RSRP values that have been found to meetsome reporting criterion, e.g., exceeding a threshold value.

When a UE is being served on multiple carrier frequencies via a PCelland one or more SCells, the UE needs to perform Radio ResourceManagement (RRM) measurements on other cells on the currently usedcarrier frequencies (i.e., intra-frequency measurements) as well as oncells on other carrier frequencies (i.e., inter-frequency measurements).Because the discovery signals are not transmitted continuously, the UEneeds to be informed about the timing of the discovery signals so as tomanage its search complexity. Furthermore, when a UE is being served onas many carrier frequencies as it is capable of supporting andinter-frequency RRM measurements need to be performed on a differentcarrier frequency that is not currently being used, the UE is assigned ameasurement gap pattern. This gap pattern on a serving frequency allowsthe UE to retune its receiver for the serving frequency to the otherfrequency on which measurements are being performed. During this gapduration, the UE cannot be scheduled by the eNB on the current servingfrequency. Knowledge of the timing of the discovery signals isespecially important when the use of such measurement gaps is needed.Beyond mitigating UE complexity, this also ensures that the UE is notunavailable for scheduling for prolonged periods of time on the currentserving frequencies (PCell or SCell).

The provision of such timing information is done via a Discovery SignalMeasurement Timing Configuration (DMTC) that is signaled to the UE. TheDMTC provides a window with a duration of 6 ms occurring with a certainperiodicity and timing within which the UE may expect to receivediscovery signals. The duration of 6 ms is the same as the measurementgap duration as currently defined in LTE and allows the measurementprocedures at the UE for discovery signals to be harmonized regardlessof the need for measurement gaps. Only one DMTC is provided per carrierfrequency including the current serving frequencies. The UE can expectthat the network will transmit discovery signals so that all cells thatare intended to be discoverable on a carrier frequency transmitdiscovery signals within the DMTCs. Furthermore, when measurement gapsare needed, it is expected that the network will ensure sufficientoverlap between the configured DMTCs and measurement gaps.

2 WLAN

In typical deployments of WLAN, Carrier Sense Multiple Access withCollision Avoidance (CSMA/CA) is used for medium access. This means thatthe channel is sensed to perform a CCA, and a transmission is initiatedonly if the channel is declared as Idle. In case the channel is declaredas Busy, the transmission is essentially deferred until the channel isdeemed to be Idle. When the range of several Access Points (APs) usingthe same frequency overlap, this means that all transmissions related toone AP might be deferred in case a transmission on the same frequency toor from another AP which is within range can be detected. Effectively,this means that if several APs are within range, they will have to sharethe channel in time, and the throughput for the individual APs may beseverely degraded. A general illustration of the LBT mechanism is shownin FIG. 6.

3 LAA to Unlicensed Spectrum Using LTE

Up to now, the spectrum used by LTE is dedicated to LTE. This has theadvantage that the LTE system does not need to take into account thecoexistence issue and the spectrum efficiency can be maximized. However,the spectrum allocated to LTE is limited and, therefore, cannot meet theever increasing demand for larger throughput from applications/services.Therefore, a new work item has been initiated in 3GPP on extending LTEto exploit unlicensed spectrum in addition to licensed spectrum.Unlicensed spectrum can, by definition, be simultaneously used bymultiple different technologies. Therefore, LTE needs to consider thecoexistence issue with other systems such as IEEE 802.11 (Wi-Fi)systems. Operating LTE in the same manner in unlicensed spectrum as inlicensed spectrum can seriously degrade the performance of Wi-Fi asWi-Fi will not transmit once it detects the channel is occupied.

Furthermore, one way to utilize the unlicensed spectrum reliably is totransmit essential control signals and channels on a licensed carrier.That is, as shown in FIG. 7, a UE is connected to a PCell in thelicensed band and one or more SCells in the unlicensed band. In thisapplication, a SCell in unlicensed spectrum is also referred to as aLicense Assisted (LA) SCell.

4 Standalone Operation in Unlicensed Spectrum Using LTE

Recently there have also been proposals to operate LTE in unlicensedspectrum without the aid of a licensed carrier. In such operation, thePCell will also operate on the unlicensed carrier and thus essentialcontrol signals and channels will also be subject to unmanagedinterference and LBT.

LTE mobility, i.e. to maintain a connection while the UE is movingbetween different network nodes, is typically done on the PCell. Whenthe PCell is operating in unlicensed spectrum, the signals used formobility, which are typically PSS/SSS and CRS, are typically transmittedrather sparsely, e.g. in the DRS occasion. In addition, they are allsubject to LBT, and thus their presence is not guaranteed.

Further, the rather dense system information broadcast messages that aretypically transmitted on the PCell will also need to be transmitted moresparsely and under LBT constraints.

5 Network Synchronization

Network synchronization refers to the degree of time and frequencysynchronization the network nodes have. The degree of synchronizationtypically varies from (1) tight, enough for advanced transmissiontechniques, which in today's LTE system is on the microsecond level, (2)coarse synchronization, which is enough for aligning, e.g., DRSoccasions with DMTC windows and measurement gaps and is typically on themillisecond level, and (3) no synchronization.

6 Problem

Particularly when operating in the unlicensed spectrum, some cells maybe synchronized while others may not. This presents new challenges withrespect to DMTC. As such, there is a need for systems and methods thataddress these challenges.

SUMMARY

Systems and methods relating to Discovery Signal Measurement TimingConfiguration (DMTC) are disclosed. In some embodiments, a method ofoperation of a radio access node in a cellular communications networkcomprises sending, to a wireless device, a DMTC for one of a groupconsisting of: (a) a frequency on which one or more asynchronous cellsare operating, an asynchronous cell being a cell that is unsynchronizedwith a Primary Cell (PCell) of the wireless device, and (b) a SecondaryCell (SCell) configured for the wireless device such that the DMTC is aspecific DMTC for the SCell. A DMTC configuration that is specific to aSCell provides improved measurement performance on the SCell because,e.g., the DMTC configuration can be specifically tailored to that SCell.A DMTC configuration for a frequency on which one or more asynchronouscells are operating provides improved measurement performance on thatcarrier.

In some embodiments, the DMTC is a DMTC for a SCell configured for thewireless device. Further, in some embodiments, sending the DMTCcomprises sending, to the wireless device, a message that configures theSCell for the wireless device, the message comprising the DMTC for theSCell such that the DMTC is a specific DMTC for the SCell. In someembodiments, the message is an RRCConnectionReconfiguration message.

In some embodiments, the DMTC is a DMTC for the frequency on which oneor more asynchronous cells are operating. Further, in some embodiments,sending the DMTC comprises transmitting system information comprising anindication of whether one or more intra-frequency asynchronous cells areoperating on the frequency and the DMTC for the frequency to be used bythe wireless device if the indication is set to a value that indicatesthat one or more intra-frequency asynchronous cells are operating on thefrequency. In some embodiments, the system information is a SystemInformation Block type 3 (SIB3) information element. In some otherembodiments, sending the DMTC comprises transmitting system informationcomprising an indication of whether one or more inter-frequencyasynchronous cells are operating on the frequency and the DMTC for thefrequency to be used by the wireless device if the indication is set toa value that indicates that one or more inter-frequency asynchronouscells are operating on the frequency. In some embodiments, the systeminformation is a SIB type 5 (SIB5) information element. In some otherembodiments, sending the DMTC comprises transmitting a measurementobject to the wireless device, the measurement object comprising anindication of whether one or more asynchronous cells are operating onthe frequency and the DMTC for the frequency to be used by the wirelessdevice if the indication is set to a value that indicates that one ormore asynchronous cells are operating on the frequency.

In some embodiments, sending the DMTC comprises sending the DMTC and asecond DMTC, the DMTC and the second DMTC being separate DMTCs and oneof the DMTCs is associated with an asynchronous indication and the otherDMTC is associated with a synchronous indication.

In some embodiments, the DMTC is a DMTC for the frequency on which oneor more asynchronous cells are operating, and sending the DMTC comprisessending the DMTC together with an asynchronous indication that indicateswhether any asynchronous cells are operating on the frequency and asecond DMTC for the frequency together with an indication of whether anysynchronous cells are operating on the frequency.

In some embodiments, the method further comprises determining whether toconfigure a cell as a SCell of the wireless device and, upon determiningto configure the cell as a SCell of the wireless device, determiningwhether an asynchronous indication has been provided for a carrierfrequency on which the cell operates. Sending the DMTC comprises, upondetermining that the asynchronous indication has been provided, sendingthe DMTC for the cell in a message that adds the cell as a SCell of thewireless device.

Embodiments of a radio access node for a cellular communications networkare also disclosed. In some embodiments, a radio access node for acellular communications network comprises a processor and memorycomprising instructions executable by the processor whereby the radioaccess node is operable to send, to a wireless device, a DMTC for one ofa group consisting of: (a) a frequency on which one or more asynchronouscells are operating, an asynchronous cell being a cell that isunsynchronized with a PCell of the wireless device, and (b) a SCellconfigured for the wireless device such that the DMTC is a specific DMTCfor the SCell.

In some embodiments, a radio access node for a cellular communicationsnetwork is adapted to send, to a wireless device, a DMTC for one of agroup consisting of: (a) a frequency on which one or more asynchronouscells are operating, an asynchronous cell being a cell that isunsynchronized with a PCell of the wireless device, and (b) a SCellconfigured for the wireless device such that the DMTC is a specific DMTCfor the SCell. In some embodiments, the radio access node is furtheroperable to operate according to any one of the embodiments of themethod of operation of a radio access node disclosed herein.

In some embodiments, a radio access node for a cellular communicationsnetwork comprises a sending module operable to send, to a wirelessdevice, a DMTC for one of a group consisting of: (a) a frequency onwhich one or more asynchronous cells are operating, an asynchronous cellbeing a cell that is unsynchronized with a PCell of the wireless device,and (b) a SCell configured for the wireless device such that the DMTC isa specific DMTC for the SCell.

Embodiments of a method of operation of a wireless device in a cellularcommunications network are also disclosed. In some embodiments, a methodof operation of a wireless device in a cellular communications networkcomprises receiving a DMTC for at least one of: (a) a frequency on whichone or more asynchronous cells are operating, the one or moreasynchronous cells being one or more cells that are unsynchronized witha PCell of the wireless device, and (b) a SCell configured for thewireless device such that the DMTC is a specific DMTC for the SCell. Themethod further comprises utilizing the DMTC.

In some embodiments, the DMTC is a DMTC for a SCell configured for thewireless device. Further, in some embodiments, receiving the DMTCcomprises receiving a message that configures the SCell for the wirelessdevice, the message comprising the DMTC for the SCell such that the DMTCis a specific DMTC for the SCell. In some embodiments, the message is anRRCConnectionReconfiguration message.

In some embodiments, the DMTC is a DMTC for a frequency on which one ormore asynchronous cells are operating. Further, in some embodiments,receiving the DMTC comprises receiving system information comprising anindication of whether one or more intra-frequency asynchronous cells areoperating on the frequency and the DMTC for the frequency to be used bythe wireless device if the indication is set to a value that indicatesthat one or more intra-frequency asynchronous cells are operating on thefrequency. In some embodiments, the system information is a SIB3information element. In some other embodiments, receiving the DMTCcomprises receiving system information comprising an indication ofwhether one or more inter-frequency asynchronous cells are operating onthe frequency and the DMTC for the frequency to be used by the wirelessdevice if the indication is set to a value that indicates that one ormore inter-frequency asynchronous cells are operating on the frequency.In some embodiments, the system information is a SIB5 informationelement. In some other embodiments, receiving the DMTC comprisesreceiving a measurement object, the measurement object comprising anindication of whether one or more asynchronous cells are operating onthe frequency and the DMTC for the frequency to be used by the wirelessdevice if the indication is set to a value that indicates that one ormore asynchronous cells are operating on the frequency.

In some embodiments, receiving the DMTC comprises receiving the DMTC anda second DMTC, the DMTC and the second DMTC being separate DMTCs and oneof the DMTCs is associated with an asynchronous indication and the otherDMTC is associated with a synchronous indication.

In some embodiments, the DMTC is a DMTC for the frequency on which oneor more asynchronous cells are operating, and receiving the DMTCcomprises receiving the DMTC together with an asynchronous indicationthat indicates whether any asynchronous cells are operating on thefrequency and a second DMTC for the frequency together with anindication of whether any synchronous cells are operating on thefrequency.

In some embodiments, utilizing the DMTC comprises determining that themessage that configures the SCell for the wireless device comprises theDMTC for the SCell and, upon determining that the message comprises theDMTC for the SCell, prioritizing measurements according to the DMTC forthe SCell. Further, in some embodiments, utilizing the DMTC furthercomprises determining whether an asynchronous indication has beenreceived for a carrier frequency on which the SCell operates and, upondetermining that an asynchronous indication has been received,performing best effort measurements on neighbor cells on the carrierfrequency on which the SCell operates.

Embodiments of a wireless device for a cellular communications networkare also disclosed. In some embodiments, a wireless device for acellular communications network comprises a transceiver, a processor,and memory comprising instructions executable by the processor wherebythe wireless device is operable to receive a DMTC for at least one of:(a) a frequency on which one or more asynchronous cells are operating,the one or more asynchronous cells being one or more cells that areunsynchronized with a PCell of the wireless device, and utilize theDMTC, and (b) a SCell configured for the wireless device such that theDMTC is a specific DMTC for the SCell.

In some embodiments, a wireless device for a cellular communicationsnetwork is adapted to receive a DMTC for at least one of: (a) afrequency on which one or more asynchronous cells are operating, the oneor more asynchronous cells being one or more cells that areunsynchronized with a PCell of the wireless device, and (b) a SCellconfigured for the wireless device such that the DMTC is a specific DMTCfor the SCell. The wireless device is further adapted to utilize theDMTC. In some embodiments, the wireless device is further adapted tooperate according to any one of the embodiments of the method ofoperation of a wireless device disclosed herein.

In some embodiments, a wireless device for a cellular communicationsnetwork comprises a receiving module and a utilizing module. Thereceiving module is operable to receive a DMTC for at least one of: (a)a frequency on which one or more asynchronous cells are operating, theone or more asynchronous cells being one or more cells that areunsynchronized with a PCell of the wireless device, and (b) a SCellconfigured for the wireless device such that the DMTC is a specific DMTCfor the SCell. The utilizing module is operable to utilize the DMTC.

Those skilled in the art will appreciate the scope of the presentdisclosure and realize additional aspects thereof after reading thefollowing detailed description of the embodiments in association withthe accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the disclosure, andtogether with the description serve to explain the principles of thedisclosure. In the drawings, like reference labels denote like features.

FIG. 1 illustrates a Long Term Evolution (LTE) downlink physicalresource;

FIG. 2 illustrates an LTE time-domain structure;

FIG. 3 illustrates an example of an LTE downlink subframe;

FIG. 4 illustrates Carrier Aggregation (CA);

FIG. 5 illustrates one example of a discovery signal in LTE;

FIG. 6 illustrates Listen-Before-Talk (LBT);

FIG. 7 illustrates License Assisted Access (LAA) to unlicensed spectrumusing LTE CA;

FIG. 8 illustrates one example of a cellular communications network(i.e., an LTE network in this example) in which embodiments of thepresent disclosure may be implemented;

FIG. 9 illustrates a process by which a Discovery Signal MeasurementTiming Configuration (DMTC) for a Secondary Cell (SCell) is provided toa wireless device in a message in which the SCell is added (i.e.,configured) for the wireless device according to some embodiments of thepresent disclosure;

FIG. 10 illustrates a process by which a DMTC for asynchronousneighboring cells is provided to a wireless device in system informationaccording to some embodiments of the present disclosure;

FIG. 11 illustrates a process by which a DMTC for asynchronousneighboring cells is provided to a wireless device in a measurementobject according to some embodiments of the present disclosure;

FIG. 12 is a flow chart that illustrates the operation of a radio accessnode according to some embodiments of the present disclosure;

FIGS. 13 and 14 are flow charts that illustrate the operation of awireless device according to some embodiments of the present disclosure;

FIGS. 15 and 16 are block diagram of some embodiments of a wirelessdevice; and

FIGS. 17 through 19 are block diagrams of some embodiments of a radioaccess node.

DETAILED DESCRIPTION

The embodiments set forth below represent information to enable thoseskilled in the art to practice the embodiments and illustrate the bestmode of practicing the embodiments. Upon reading the followingdescription in light of the accompanying drawing figures, those skilledin the art will understand the concepts of the disclosure and willrecognize applications of these concepts not particularly addressedherein. It should be understood that these concepts and applicationsfall within the scope of the disclosure and the accompanying claims.

The following description presents various embodiments of the disclosedsubject matter. These embodiments are presented as teaching examples andare not to be construed as limiting the scope of the disclosed subjectmatter. For example, certain details of the described embodiments may bemodified, omitted, or expanded upon without departing from the scope ofthe described subject matter.

As discussed above, in a conventional Third Generation PartnershipProject (3GPP) Long Term Evolution (LTE) system, a single DiscoverySignal Measurement Timing Configuration (DMTC) is provided for eachcarrier frequency. A problem arises, particularly when operating in theunlicensed spectrum (e.g., LTE in the Unlicensed Band (LTE-U) Standaloneor MulteFire), when asynchronous cells (i.e., cells that are notsynchronized with the Primary Cell (PCell) of the User Equipment device(UE)) are operating on a frequency for which the UE is configured toperform measurements such as, e.g., Radio Resource Management (RRM)measurements for mobility purposes. In this case, it is desirable toperform measurements on both synchronized and unsynchronized cells.However, the conventional DMTC per carrier frequency assumessynchronized cells and, as such, is unsuitable for unsynchronized cells.One way to address this issue is for the UE to “look everywhere” for theDiscovery Reference Signals (DRSs) of unsynchronized cells. However,this has at least two problems. First, “looking everywhere” will resultin the UE being active for longer periods of time and, consequently, asignificant increase in power consumption. Second, the UE has no way ofknowing whether there are unsynchronized cells on the carrier frequencyand, as such, may expend valuable resources search for unsynchronizedcells when there are none. At least some of the embodiments disclosedherein address these problems.

In certain embodiments the same DMTC configuration that is provided inan enhanced System Information Block (eSIB) or MulteFire SystemInformation Block (SIB-MF) for the (primary) serving cell is also usedfor the (not yet configured) Secondary Cell(s) (SCell(s)) (“option 1”).Note that the terms “DMTC” and “DMTC configuration” are usedinterchangeably herein. In certain other embodiments, it is assumed thatthere are cells on the frequencies indicated in System Information Blocktype 5 (SIB5) that are synchronous with the PCell, and assume minimumperiodicity for the DMTC periodicity, i.e. 40 milliseconds (ms), andmaximum duration for the DMTC duration (10 ms) (“option 2”). In certainembodiments, the DMTC for the SCells is provided via dedicated signaling(“option 3”).

Certain embodiments are presented in recognition of shortcomingsassociated with alternative approaches, such as the following. Certainapproaches provide the DMTC for a frequency, resulting in reducedmeasurement performance on the SCells, such that potential data rates onthe SCells cannot be achieved.

Certain embodiments may also provide one or more benefits compared toconventional approaches. For example, in “option 1” embodiments, theinformation may be provided in a System Information Block (SIB) and in aMeasurement Object (measObject) before SCells are added. Thus, themeasurement performance for potential SCells can be improved leading tofaster decisions for the enhanced or evolved Node B (eNB) as to whetherto add another SCell for the UE or not. As another example, in “option2” embodiments where it is assumed that there are cells on thefrequencies indicated in SIB5 that are synchronous with the PCell, andminimum periodicity for the DMTC periodicity, i.e. 40 ms, and maximumduration for the DMTC duration (10 ms) are assumed, there may be bettermeasurement performance if there are potential SCells and there couldalso be some battery savings if there are synchronized cells. As yetanother example, “option 3” embodiments may exhibit improved measurementperformance on the SCells, and potentially reduced UE power consumptionif the DMTC of SCells is known and measurements on the same frequencyhave to be performed less often.

For option 1 and 2, the UE assumes that there are cell(s) on the carrierfrequencies indicated in SIB5 that may potentially be configured asSCell(s), even if the async bit is set to true. In other words, forexample, the SIB5 may include an async bit that, if set, indicates thatthere are cells on the corresponding frequency that are asynchronous.

For option 1, there are different approaches:

-   -   1a) The field description for the servCellDMTC in the        eSIB/SIB-MF could be updated to apply to the PCell and all cells        that can be configured as SCells, e.g. cells that are        potentially operated by, e.g., the serving eNB (could also be        inter-node Carrier Aggregation (CA) if the cells are tightly        synchronized and the operating eNBs have an interface for fast        data exchange).    -   1b) There could be an additional bit indicating in the SIB-MF        that the servCellDMTC shall be used for the SCells.    -   1c) There could be an additional bit in SIB5 indicating that the        eNB operates synchronous cells on the carrier frequency        indicated by (dl-)CarrierFreq, e.g. syncNeighCells.    -   1d) There could be an additional bit in the measObject        indicating that the eNB operates synchronous cells on the        carrier frequency indicated by (dl-)CarrierFreq, e.g.        syncNeighCells. For options 1c and 1d, the eNB could provide the        UE with accurate DMTC configuration.    -   1e) There are two separate DMTC configurations, one together        with the async indication (where the DMTC could be empty), and        one together with the sync indication. Notably, these two        indications may be implemented in any suitable manner. As will        be appreciated by one of skill in the art, the two indications        may be implemented as different parameters (e.g., an async        parameter and a sync parameter) or as a single parameter. As an        example, the two indications may be implemented as a single        async parameter where the async parameter operates as both an        async indication and a sync indication.

One example for SIB5 and, e.g., measObject:

[[ asyncNeighCells-MF BOOLEAN OPTIONAL -- Need OP neighborCellDMTC-MFMeasDS-Config-MF OPTIONAL -- Need OP ]]This example for SIB5 and, e.g., measObject may be used to provide anasync indication (referred to as asyncNeighCells-MF) that, if set,indicates that there are asynchronous cells on the respective frequency.If the async indication is set to a value that indicates that one ormore asynchronous neighbor cells are operating on the frequency, thenthe DMTC (neighborCellDMTC-MF) is the DMTC for the asynchronous neighborcells (i.e., cells that are not serving cells of the UE that operate onthe respective frequency identified by SIB5 or measObject).

Example for options 1c/1d in SIB5 and, e.g., measObject:

[[ asyncNeighCells-MF BOOLEAN OPTIONAL -- Need OP syncNeighCell-MFBOOLEAN OPTIONAL -- Need OP neighborCellDMTC-MF MeasDS-Config-MFOPTIONAL -- Need OP ]]This example is for SIB5 and, e.g., measObject where there is anadditional indication of whether there are any synchronous cells on therespective frequency.

Example for option 1e in SIB5 and, e.g., measObject:

[[ asyncNeighCellInfo-MF SEQUENCE { asyncNeighCells-MF ENUMERATED{true},asyncNeighCellDMTC-MF MeasDS-Config-MF OPTIONAL -- Need OP }, OPTIONAL-- Need OP syncNeighCellDMTC-MF MeasDS-Config-MF OPTIONAL -- Need OP ]]This example is for SIB5 and, e.g., measObject where the SIB5 ormeasurement object includes both: (a) a DMTC for asynchronous cells(asyncNeighCellDMTC-MF) together with the async indication(asyncNeighCells-MF) and (b) a separate DMTC for synchronous cells(syncNeighCellDMTC-MF). While not illustrated in this example, asdiscussed above, the DMTC for synchronous cells may be provided togetherwith a sync indication, i.e., an indication of whether there are anysynchronous cells on the respective frequency.

For the non-synchronized neighbor cells, the DMTC is only provided ifavailable.

For option 2, a sync bit could also be added to SIB5 and the measObjectto make the UE aware that there are unsynchronized cells, synchronizedcells, or even both on the carrier frequency identified by(dl-)CarrierFreq.

Option 3 can be combined with option 1 or option 2, respectively.

The embodiments described herein may be implemented in any appropriatetype of communication system supporting any suitable communicationstandards and using any suitable components. As one example, certainembodiments may be implemented in an LTE network, such as thatillustrated in FIG. 8. Referring to FIG. 8, a communication network 10comprises a plurality of wireless communication devices 12 (e.g., UEssuch as, but not limited to, regular UEs, Machine Type Communication(MTC)/Machine-to-Machine (M2M) UEs, or the like) and a plurality ofradio access nodes 14 (e.g., eNBs or other base stations). The wirelesscommunication devices 12 are also referred to herein as wireless devices12. Further, it is to be understood that the UEs referred to herein areone embodiment of the wireless devices 12. The communication network 10is organized into cells 16, which are connected to a core network 18 viathe corresponding radio access nodes 14. The radio access nodes 14 arecapable of communicating with the wireless communication devices 12along with any additional elements suitable to support communicationbetween wireless communication devices or between a wirelesscommunication device and another communication device (such as alandline telephone).

As discussed above, there may be multiple levels of DMTC. Specifically,at one level, the network (e.g., the radio access node 14, which may be,e.g., an eNB) provides a DMTC to the wireless device 12 (e.g., UE) thatis specific for a configured (i.e., an added) SCell of the wirelessdevice 12. In this case, the DMTC may be provided via dedicatedsignaling such as, for example, an RRCConnectionReconfiguration messagein which the SCell is configured for the wireless device 12. By beingspecifically for the SCell, the DMTC may be narrowly tailored for thatparticular SCell, which in turn improves performance of the wirelessdevice 12. At another level, the network (e.g., radio access node 14)provides a DMTC to the wireless device 12 for synchronous cells on aparticular carrier frequency. In this case, the DMTC may be included insystem information (e.g., SIB3 or SIB5) or included in a measurementobject used to configure the wireless device 12 to perform measurementson that carrier frequency. Since the cells are synchronous, the DMTCconfiguration may be tailored to synchronous cells (i.e., does not needto accommodate asynchronous cells), which in turn improves performance.At yet another level, the network (e.g., radio access node 14) providesa DMTC to the wireless device 12 for asynchronous cells on a particularcarrier frequency. In this case, the DMTC may be included in systeminformation (e.g., SIB3 or SIB5) or included in a measurement objectused to configure the wireless device 12 to perform measurements on thatcarrier frequency. Since the cells are asynchronous, the DMTCconfiguration may be tailored to asynchronous cells (e.g., longer DMTCduration or window than for synchronous cells) while still keeping thewireless device 12 from having to, e.g., search in all possible timeresources for discovery signals from the asynchronous cells. Further, insome embodiments, the async indication and/or the sync indication informthe wireless device 12 as to whether there are asynchronous cells and/orsynchronous cells on the respective carrier frequency. This furtherenables the wireless device 12 to use appropriate DMTC.

In this regard, FIG. 9 illustrates the operation of the radio accessnode 14 and the wireless device 12 according to some embodiments of thepresent disclosure in which the radio access node 14 provides a DMTC tothe wireless device 12 for a SCell configured (i.e., added) for thewireless device 12 via dedicated signaling. As illustrated, in thisexample, the radio access node 14 sends an RRCConnectionReconfigurationmessage to the wireless device 12, where theRRCConnectionReconfiguration message configures one or more SCells forthe wireless device 12 and includes, for each configured SCell, a DMTCspecifically for the configured SCell (step 100). Note that theRRCConnectionReconfiguration message is only one example of dedicatedsignaling. Other types of dedicated signaling may alternatively be used.The wireless device 12 utilizes the DMTC(s) for the configured, oradded, SCell(s) (step 102). The wireless device 12 may use the DMTCs toperform measurements such as RRM measurements on the configuredSCell(s).

Below, example ASN.1 coded for dedicated Radio Resource Control (RRC)signaling and a new RRCConnectionReconfiguration message including theSCell DMTC are provided. Portions relating to the DMTC for the SCell arein bold and italicized.

The RRCConnectionReconfiguration message is the command to modify an RRCconnection. It may convey information for measurement configuration,mobility control, radio resource configuration (including resourceblocks, Medium Access Control (MAC) main configuration, and physicalchannel configuration) including any associated dedicated Non-AccessStratum (NAS) information and security configuration.

ASN.1 Code for Dedicated RRC Signaling (from 3GPP TechnicalSpecification (TS) 36.331):

RRCConnectionReconfiguration-v1020-IEs ::= SEQUENCE {sCellToReleaseList-r10 SCellToReleaseList-r10 OPTIONAL, -- Need ONsCellToAddModList-r10 SCellToAddModList-r10 OPTIONAL, -- Need ONnonCriticalExtension RRCConnectionReconfiguration-v1130-IEs OPTIONAL }

RRCConnectionReconfiguration message -- ASN1STARTRRCConnectionReconfiguration ::= SEQUENCE { rrc-TransactionIdentifierRRC-TransactionIdentifier, criticalExtensions CHOICE { c1 CHOICE{rrcConnectionReconfiguration-r8 RRCConnectionReconfiguration-r8-IEs,spare7 NULL, spare6 NULL, spare5 NULL, spare4 NULL, spare3 NULL, spare2NULL, spare1 NULL }, criticalExtensionsFuture SEQUENCE { } } }RRCConnectionReconfiguration-r8-IEs ::= SEQUENCE { measConfig MeasConfigOPTIONAL, -- Need ON mobilityControlInfo MobilityControlInfoOPTIONAL, -- Cond HO dedicatedInfoNASList SEQUENCE (SIZE (1..maxDRB)) OFDedicatedInfoNAS OPTIONAL, -- Cond nonHO radioResourceConfigDedicatedRadioResourceConfigDedicated OPTIONAL, -- Cond HO-toEUTRAsecurityConfigHO SecurityConfigHO OPTIONAL, -- Cond HOnonCriticalExtension RRCConnectionReconfiguration-v890-IEs OPTIONAL }RRCConnectionReconfiguration-v890-IEs ::= SEQUENCE {lateNonCriticalExtension OCTET STRING (CONTAININGRRCConnectionReconfiguration-v8m0-IEs) OPTIONAL, nonCriticalExtensionRRCConnectionReconfiguration-v920-IEs OPTIONAL } -- Late non-criticalextensions: RRCConnectionReconfiguration-v8m0-IEs ::= SEQUENCE { --Following field is only for pre REL-10 late non-critical extensionslateNonCriticalExtension OCTET STRING OPTIONAL, nonCriticalExtensionRRCConnectionReconfiguration-v10i0-IEs OPTIONAL }RRCConnectionReconfiguration-v10i0-IEs ::= SEQUENCE {antennaInfoDedicatedPCell-v10i0 AntennaInfoDedicated-v10i0 OPTIONAL, - -Need ON -- Following field is only for late non-critical extensions fromREL-10 nonCriticalExtension SEQUENCE { } OPTIONAL } -- Regularnon-critical extensions: RRCConnectionReconfiguration-v920-IEs ::=SEQUENCE { otherConfig-r9 OtherConfig-r9 OPTIONAL, -- Need ONfullConfig-r9 ENUMERATED {true} OPTIONAL, -- Cond HO-ReestabnonCriticalExtension RRCConnectionReconfiguration-v10i0-IEs OPTIONAL }RRCConnectionReconfiguration-v1020-IEs ::= SEQUENCE {sCellToReleaseList-r10 SCellToReleaseList-r10 OPTIONAL, -- Need ONsCellToAddModList-r10 SCellToAddModList-r10 OPTIONAL, -- Need ONnonCriticalExtension RRCConnectionReconfiguration-v1130-IEs OPTIONAL }RRCConnectionReconfiguration-v1130-IEs ::= SEQUENCE {systemInfomationBlockType1Dedicated-r11 OCTET STRING (CONTAININGSystemInformationBlockType1) OPTIONAL, -- Need ON nonCriticalExtensionRRCConnectionReconfiguration-v1250-IEs OPTIONAL }RRCConnectionReconfiguration-v1250-IEs ::= SEQUENCE {wlan-OffloadInfo-r12 CHOICE { release NULL, setup SEQUENCE {wlan-OffloadConfigDedicated-r12 WLAN-OffloadConfig-r12, t350-r12ENUMERATED (min5, min10, min20, min30, min60,  min120, min180, spare1}OPTIONAL - - Need OR } } OPTIONAL, - - Need ON scg-Configuration-r12SCG-Configuration-r12 OPTIONAL, -- Cond nonFullConfigs1-SyncTxControl-r12 SL-SyncTxControl-r12 OPTIONAL, -- Need ONs1-DiscConfig-r12 SL-DiscConfig-r12 OPTIONAL, -- Need ONs1-CommConfig-r12 SL-CommConfig-r12 OPTIONAL, -- Need ONnonCriticalExtension RRCConnectionReconfiguration-v1310-IEs OPTIONAL }RRCConnectionReconfiguration-v1310-IEs ::= SEQUENCE {sCellToReleaseListExt-r13 SCellToReleaseListExt-r13 OPTIONAL, -- Need ONsCellToAddModListExt-r13 SCellToAddModListExt-r13 OPTIONAL, -- Need ONlwa-Configuration-r13 LWA-Configuration-r13 OPTIONAL, -- Need ONlwip-Configuration-r13 LWIP-Configuration-r13 OPTIONAL, -- Need ONsteeringCommandWLAN-r13 CHOICE { release NULL, setup SEQUENCE { commandCHOICE { steerToWLAN-r13 WLAN-Id-List-r12, steerToLTE-r13 NULL }, ... }} OPTIONAL, -- Need ON nonCriticalExtensionRRCConnectionReconfiguration-MF-IEs OPTIONAL }

 

 --

 --

 --

 --

...

 --

SL-SyncTxControl-r12 ::= SEQUENCE { networkControlledSyncTx-r12ENUMERATED {on, off} OPTIONAL - - Need OP } PSCellToAddMod-r12 ::=SEQUENCE { sCellIndex-r12 SCellIndex-r10, cellIdentification-r12SEQUENCE { physCellId-r12 PhysCellId, dl-CarrierFreq-r12ARFCN-ValueEUTRA-r9 } OPTIONAL, Cond SCellAddradioResourceConfigCommonPSCell-r12 RadioResourceConfigCommonPSCell-r12OPTIONAL, -- Cond SCellAdd radioResourceConfigDedicatedPSCell-r12RadioResourceConfigDedicatedPSCell-r12 OPTIONAL, -- Cond SCellAdd2 ...,[[ antennaInfoDedicatedPSCell-v1280AntennaInfoDedicated-v10i0 OPTIONAL - - Need ON ]], [[ sCellIndex-r13SCellIndex-r13 OPTIONAL -- Need ON ]] } PowerCoordinationInfo-r12 ::=SEQUENCE { p-MeNB-r12 INTEGER (1..16), p-SeNB-r12 INTEGER (1..16),powerControlMode-r12 INTEGER (1..2) } SCellToAddModList-r10 ::= SEQUENCE(SIZE (1..maxSCell-r10)) OF SCellToAddMod-r10 SCellToAddModListExt-r13::= SEQUENCE (SIZE (1..maxSCell-r13)) OF SCellToAddModExt-r13

 

 

SCellToAddMod-r10 ::= SEQUENCE { sCellIndex-r10 SCellIndex-r10,cellIdentification-r10 SEQUENCE { physCellId-r10 PhysCellId,dl-CarrierFreq-r10 ARFCN-ValueEUTRA } OPTIONAL, -- Cond SCellAddradioResourceConfigCommonSCell-r10 RadioResourceConfigCommonSCell-r10OPTIONAL, -- Cond SCellAdd radioResourceConfigDedicatedSCell-r10RadioResourceConfigDedicatedSCell-r10 OPTIONAL, -- Cond SCellAdd2 ...,[[ dl-CarrierFreq-v1090 ARFCN-ValueEUTRA-v9e0 OPTIONAL -- CondEARFCN-max ]], [[ antennaInfoDedicatedSCell-v10i0AntennaInfoDedicated-v10i0 OPTIONAL -- Need ON ]]

 --

} SCellToAddModExt-r13 ::= SEQUENCE { sCellIndex-r13 SCellIndex-r13,cellIdentification-r13 SEQUENCE { physCellId-r13 PhysCellId,dl-CarrierFreq-r13 ARFCN-ValueEUTRA-r9 } OPTIONAL, -- Cond SCellAddradioResourceConfigCommonSCell-r13 RadioResourceConfigCommonSCell-r10OPTIONAL, -- Cond SCellAdd radioResourceConfigDedicatedSCell-r13RadioResourceConfigDedicatedSCell-r10 OPTIONAL, -- Cond SCellAdd2antennaInfoDedicatedSCell-r13 AntennaInfoDedicated-v10i0 OPTIONAL - -Need ON}

 --

--

--

 - - 

 - - 

...

SCellToReleaseList-r10 ::= SEQUENCE (SIZE (1..maxSCell-r10)) OFSCellIndex-r10 SCellToReleaseListExt-r13 ::= SEQUENCE (SIZE(1..maxSCell-r13)) OF SCellIndex- r13 SCG-Configuration-r12 ::= CHOICE {release NULL, setup SEQUENCE { scg-ConfigPartMCG-r12 SEQUENCE {scg-Counter-r12 INTEGER (0.. 65535) OPTIONAL, - - Need ONpowerCoordinationInfo-r12 PowerCoordinationInfo-r12 OPTIONAL, - - NeedON ... } OPTIONAL, -- Need ON scg-ConfigPartSCG-r12SCG-ConfigPartSCG-r12 OPTIONAL -- Need ON } } SCG-ConfigPartSCG-r12 ::=SEQUENCE { radioResourceConfigDedicatedSCG-r12RadioResourceConfigDedicatedSCG-r12 OPTIONAL, - - Need ONsCellToReleaseListSCG-r12 SCellToReleaseList-r10 OPTIONAL, -- Need ONpSCellToAddMod-r12 PSCellToAddMod-r12 OPTIONAL, -- Need ONsCellToAddModListSCG-r12 SCellToAddModList-r10 OPTIONAL, -- Need ONmobilityControlInfoSCG-r12 MobilityControlInfoSCG-r12 OPTIONAL, -- NeedON ..., [[ sCellToReleaseListSCG-Ext-r13 SCellToReleaseListExt-r13OPTIONAL, - - Need ON sCellToAddModListSCG-Ext-r13SCellToAddModListExt-r13 OPTIONAL - - Need ON ]] } SecurityConfigHO ::=SEQUENCE { handoverType CHOICE { intraLTE SEQUENCE {securityAlgorithmConfig SecurityAlgorithmConfig OPTIONAL, - - CondfullConfig keyChangeIndicator BOOLEAN, nextHopChainingCountNextHopChainingCount }, interRAT SEQUENCE { securityAlgorithmConfigSecurityAlgorithmConfig, nas-SecurityParamToEUTRA OCTET STRING (SIZE(6))} }, ... } -- ASN1STOP

RRCConnectionReconfiguration field descriptions dedicatedInfoNASListThis field is used to transfer UE specific NAS layer information betweenthe network and the UE. The RRC layer is transparent for each PDU in thelist. fullConfig Indicates the full configuration option is applicablefor the RRC Connection Reconfiguration message. keyChangeIndicator trueis used only in an intra-cell handover when a K_(eNB) key is derivedfrom a K_(ASME) key taken into use through the latest successful NAS SMCprocedure, as described in TS 33.401 [32] for K_(eNB) re-keying. falseis used in an intra-LTE handover when the new K_(eNB) key is obtainedfrom the current K_(eNB) key or from the NH as described in TS 33.401[32]. lwa-Configuration This field is used to provide parameters for LWAconfiguration. lwip-Configuration This field is used to provideparameters for LWIP configuration. measDS-Config Parameters applicableto discovery signals measurement for the SCell indicated by theSCellIndex on the carrier frequency indicated by dl-CarrierFreq. Anyother DMTC configuration provided for the carrier frequency indicated bydl-CarrierFreq shall still apply for the neighbor cells on that carrierfrequency. nas-securityParamToEUTRA This field is used to transfer UEspecific NAS layer information between the network and the UE. The RRClayer is transparent for this field, although it affects activation ofAS- security after inter-RAT handover to E- UTRA. The content is definedin TS 24.301. networkControlledSyncTx This field indicates whether theUE shall transmit synchronisation information (i.e. becomesynchronisation source). Value On indicates the UE to transmitsynchronisation information while value Off indicates the UE to nottransmit such information. nextHopChainingCount Parameter NCC: See TS33.401 [32] p-MeNB Indicates the guaranteed power for the MeNB, asspecified in 36.213 [23]. The value N corresponds to N-1 in TS 36.213[23]. powerControlMode Indicates the power control mode used in DC.Value 1 corresponds to DC power control mode 1 and value 2 indicates DCpower control mode 2, as specified in 36.213 [23]. p-SeNB Indicates theguaranteed power for the SeNB as specified in 36.213 [23, Table5.1.4.2-1]. The value N corresponds to N-1 in TS 36.213 [23]. sCellIndexIn case of DC, the SCellIndex is unique within the scope of the UE i.e.an SCG cell can not use the same value as used for an MCG cell. ForpSCellToAddMod, if sCellIndex-r13 is present the UE shall ignoresCellIndex-r12. sCellIndex-r13 in sCellToAddModListExt-r13 shall nothave same values as sCellIndex-r10 in sCellToAddModList-r10.sCellToAddModList, sCellToAddModListExt Indicates the SCell to be addedor modified. Indexes 1 . . . 7 can be assigned using eithersCellToAddModList or sCellToAddModListExt. sCellToAddModListSCGIndicates the SCG cell to be added or modified. The field is used forSCG cells other than the PSCell (which is added/modified by fieldpSCellToAddMod). sCellToReleaseListSCG Indicates the SCG cell to bereleased. The field is also used to release the PSCell e.g. upon changeof PSCell, upon system information change for the PSCell. scg-Counter Acounter used upon initial configuration of SCG security as well as uponrefresh of S-K_(eNB). E-UTRAN includes the field upon SCG change whenone or more SCG DRBs are configured. Otherwise E-UTRAN does not includethe field. steeringCommandWLAN WLAN traffic steering command asspecified in 5.6.16.2. t350 Timer T350 as described in section 7.3.Value minN corresponds to N minutes.

FIG. 10 illustrates the operation of the radio access node 14 and thewireless device 12 according to some embodiments of the presentdisclosure in which a DMTC(s) is provided to the wireless device 12 fora carrier frequency(ies) together with a respective async indication(s)within system information. As illustrated, the radio access node 14sends a SIB (e.g., SIB3 and/or SIB5) to the wireless device 12 where theSIB includes: (a) an async indication(s) for a respective downlinkcarrier frequency(ies) and (b) for each downlink carrier frequency, aDMTC configuration to be used if the async indication for the downlinkcarrier frequency is set to a value that indicates that one or moreasynchronous cells are operating on the downlink carrier frequency(i.e., indicates that there are asynchronous cell(s) on the downlinkcarrier frequency) (step 200). The wireless device 12 utilizes theDMTC(s) for the carrier frequency(ies) (step 202). The wireless device12 may use the DMTC(s) to perform measurements such as RRM measurementson the asynchronous cells on the respective carrier frequency(ies)indicated in the SIB.

Below, examples of SIB3 and SIB5 including the async indication and DMTCconfiguration are provided. Note that, as discussed above, SIB3 and/orSIB5 may be further modified to include, for each downlink carrierfrequency specified in the SIB3/SIB5, a separate DMTC configuration forsynchronous cells on the downlink carrier frequency and, in someembodiments, a sync indication that, if set, indicates that there aresynchronous cells on the downlink carrier frequency (and thus that thewireless device 12 should use the DMTC provided for synchronous cellsto, e.g., perform RRM measurements). In the example below, portionsrelated to DMTC and async indication are bolded and italicized.

The Information Element (IE) SystemInformationBlockType3 contains cellre-selection information common for intra-frequency, inter-frequency,and/or inter-Radio Access Technology (RAT) cell re-selection (i.e.,applicable for more than one type of cell re-selection but notnecessarily all) as well as intra-frequency cell re-selectioninformation other than neighboring cell related information.

SystemInformationBlockType3 information element -- ASN1STARTSystemInformationBlockType3 ::= SEQUENCE { cellReselectioniInfoCommonSEQUENCE { q-Hyst ENUMERATED { dB0, dB1, dB2, dB3, dB4, dB5, dB6, dB8,dB10, dB12, dB14, dB16, dB18, dB20, dB22, dB24},speedStateReselectionPars SEQUENCE { mobilityStateParametersMobilityStateParameters, q-HystSF SEQUENCE { sf-Medium ENUMERATED {dB-6, dB-4, dB-2, dB0}, sf-High ENUMERATED { dB-6, dB-4, dB-2, dB0} } }OPTIONAL - - Need OP }, cellReselectionServingFreqInfo SEQUENCE {s-NonIntraSearch ReselectionThreshold OPTIONAL, - - Need OPthreshServingLow ReselectionThreshold, cellReselectionPriorityCellReselectionPriority }, intraFreqCellReselectionInfo SEQUENCE {q-RxLevMin Q-RxLevMin, p-Max P-Max OPTIONAL, - - Need OP s-IntraSearchReselectionThreshold OPTIONAL, - - Need OP allowedMeasBandwidthAllowedMeasBandwidth OPTIONAL, - - Need OP presenceAntennaPort1PresenceAntennaPort1, neighCellConfig NeighCellConfig,t-ReselectionEUTRA T-Reselection, t-ReselectionEUTRA-SFSpeedStateScaleFactors OPTIONAL - - Need OP }, ...,lateNonCriticalExtension OCTET STRING (CONTAININGSystemInformationBlockType3-v10j0-IEs) OPTIONAL, [[ s-IntraSearch-v920SEQUENCE { s-IntraSearchP-r9 ReselectionThreshold, s-IntraSearchQ-r9ReselectionThresholdQ-r9 } OPTIONAL, - - Need OP s-NonIntraSearch-v920SEQUENCE { s-NonIntraSearchP-r9 ReselectionThreshold,s-NonIntraSearchQ-r9 ReselectionThresholdQ-r9 } OPTIONAL, - - Need OPq-QualMin-r9 Q-QualMin-r9 OPTIONAL, - - Need OP threshServingLowQ-r9ReselectionThresholdQ-r9 OPTIONAL - - Need OP ]], [[ q-QualMinWB-r11Q-QualMin-r9 OPTIONAL -- Cond WB-RSRQ ]],[[ q-QualMinRSRQ-OnAllSymbols-r12 Q-QualMin-r9 OPTIONAL -- Cond RSRQ ]],[[ cellReselectionServingFreqInfo-v1310CellReselectionServingFreqInfo-v1310 OPTIONAL, -- Need OPredistributionServingInfo-r13 RedistributionServingInfo-r13 OPTIONAL, --Need OR cellSelectionInfoCE-r13 CellSelectionInfoCE-r13 OPTIONAL, --Need OP t-ReselectionEUTRA-CE-r13 T-ReselectionEUTRA-CE-r13 OPTIONAL --Need OP ]],

 - - 

 - - 

} RedistributionServingInfo-r13 ::= SEQUENCE {redistributionFactorServing-r13 INTEGER(0..10),redistributionFactorCell-r13 ENUMERATED {true} OPTIONAL, -- Need OPt360-r13 ENUMERATED {min4, min8, min16, mi in32, infinity, spare3,spare2, spare1}, redistrOnPagingOnly-r13 ENUMERATED {true}OPTIONAL --Need OP } CellReselectionServingFreqInfo-v1310 ::= SEQUENCE {cellReselectionSubPriority-r13 CellReselectionSubPriority-r13 } -- Latenon critical extensions SystemInformationBlockType3-v10j0-IEs ::=SEQUENCE { freqBandInfo-r10 NS-PmaxList-r10 OPTIONAL, -- Need ORmultiBandInfoList-v10j0 MultiBandInfoList-v10j0 OPTIONAL, -- Need ORnonCriticalExtension SEQUENCE { } OPTIONAL } -- ASN1STOP

SystemInformationBlockType3 field descriptions allowedMeasBandwidth Ifabsent, the value corresponding to the downlink bandwidth indicated bythe dl-Bandwidth included in MasterInformationBlock applies.cellSelectionInfoCE Parameters included in coverage enhancement Scriteria. They may be used by the UE to select/reselect a cell in whichit works in CE mode on the concerned non serving frequency. If absent,the UE acquires the information from the target cell on the concernedfrequency. cellReselectionInfoCommon Cell re-selection informationcommon for cells. cellReselectionServingFreqInfo Information common forCell re-selection to inter-frequency and inter-RAT cells. freqBandInfo Alist of additionalPmax and additionalSpectrumEmission values as definedin TS 36.101 [42, table 6.2.4-1] applicable for the intra-frequencyneighouring E-UTRA cells if the UE selects the frequenby band fromfreqBandIndicator in SystemInformationBlockType1.intraFreqAsyncNeighCells Indicates whether the intra-frequency neighborcells are unsynchronized with the PCell. If present, the UE shallperform intra-frequency discovery signals measurement according to theintraFreqDMTC. If intraFreqAsyncNeighCells is set to true, andintraFreqDMTC is not present, the UE performs intra-frequency discoverysignals measurement on neighbour cells assuming any possible discoverysignals timing, intraFreqcellReselectionInfo Cell re-selectioninformation common for intra-frequency cells. intraFreqDMTC Indicatesthe discovery signals measurement timing configuration (DMTC) forintra-frequency neighbour cells. multiBandInfoList-v10j0 A list ofadditionalPmax and additionalSpectrumEmission values as defined in TS36.101 [42, table 6.2.4-1] applicable for the intra-frequencyneighouring E-UTRA cells if the UE selects the frequenby bands inmultiBandInfoList (i.e. without suffix) or multiBandInfoList-v9e0. IfE-UTRAN includes multiBandInfoList- v10j0, it includes the same numberof entries, and listed in the same order, as in multiBandInfoList (i.e.without suffix). p-Max Value applicable for the intra-frequencyneighbouring E-UTRA cells. If absent the UE applies the maximum poweraccording to the UE capability. redistrOnPagingOnly If this field ispresent and the UE is redistribution capable, the UE shall only wait forthe paging message to trigger E-UTRAN inter-frequency redistributionprocedure as specified in 5.2.4.10 of 36.304[4]. q-Hyst ParameterQ_(hyst) in 36.304 [4], Value in dB. Value dB 1 corresponds to 1 dB, dB2 corresponds to 2 dB and so on. q-HystSF Parameter “Speed dependentScalingFactor for Q_(hyst)” in TS 36.304 [4]. The sf-Medium and sf-Highconcern the additional hysteresis to be applied, in Medium and HighMobility state respectively, to Q_(hyst) as defined in TS 36.304 [4]. IndB. Value dB −6 corresponds to −6 dB, dB −4 corresponds to −4 dB and soon. q-QualMin Parameter “Q_(qualmin)” in TS 36.304 [4], applicable forintra-frequency neighrbour cells. If the field is not present, the UEapplies the (default) value of negative infinity for Q_(qualmin).NOTE 1. q-QualMinRSRQ-OnAllSymbols If this field is present andsupported by the UE, the UE shall, when performing RSRQ measurements,perform RSRQ measurement on all OFDM symbols in accordance with TS36.214 [48]. NOTE 1. q-QualMinWB If this field is present and supportedby the UE, the UE shall, when performing RSRQ measurements, use a widerbandwidth in accordance with TS 36.133 [16]. NOTE 1. q-RxLevMinParameter “Q_(rxlevmin)” in TS 36.304 [4], applicable forintra-frequency neighbour cells. redistributionFactorCell IfredistributionFactorCell is present, redistributionFactorServing is onlyapplicable for the serving cell otherwise it is applicable for servingfrequency redistributionFactorServing ParameterredistributionFactorServing in TS 36.304 [4]. s-IntraSearch Parameter“S_(IntraSearchP)” in TS 36.304 [4]. If the field s-IntraSearchP ispresent, the UE applies the value of s- IntraSearchP instead. Otherwiseif neither s-IntraSearch nor s-IntraSearchP is present, the UE appliesthe (default) value of infinity for S_(IntraSearchP). s-IntraSearchPParameter “S_(IntraSearchP)” in TS 36.304 [4]. See descriptions unders-IntraSearch. s-IntraSearchQ Parameter “S_(IntraSearchQ)” in TS 36.304[4]. If the field is not present, the UE applies the (default) value of0 dB for S_(IntraSearchQ). s-NonIntraSearch Parameter“S_(nonIntraSearchP)” in TS 36.304 [4]. If the field s-NonIntraSearchPis present, the UE applies the value of s-NonIntraSearchP instead.Otherwise if neither s-NonIntraSearch nor s-NonIntraSearchP is present,the UE applies the (default) value of infinity for S_(nonIntraSearchP).s-NonIntraSearchP Parameter “S_(nonIntraSearchP)” in TS 36.304 [4]. Seedescriptions under s-NonIntraSearch. s-NonIntraSearchQ Parameter“S_(nonIntraSearchQ)” in TS 36.304 [4]. If the field is not present, theUE applies the (default) value of 0 dB for S_(nonIntraSearchQ).speedStateReselectionPars Speed dependent reselection parameters, see TS36.304 [4]. If this field is absent, i.e, mobilityStateParameters isalso not present, UE behaviour is specified in TS 36.304 [4]. t360Parameter “T360” in TS 36.304 [4]. threshServingLow Parameter“Thresh_(Serving, LowP)” in TS 36.304 [4]. threshServingLowQ Parameter“Thresh_(Serving, LowQ)” in TS 36.304 [4]. t-ReselectionEUTRA Parameter“Treselection_(EUTRA)” in TS 36.304 [4]. t-ReselectionEUTRA-SF Parameter“Speed dependent ScalingFactor for Treselection_(EUTRA)” in TS 36.304[4]. If the field is not present, the UE behaviour is specified in TS36.304 [4].

The IE SystemInformationBlockType5 contains information relevant onlyfor inter-frequency cell re-selection, i.e. information about otherEvolved Universal Terrestrial Radio Access (E-UTRA) frequencies andinter-frequency neighboring cells relevant for cell re-selection. The IEincludes cell re-selection parameters common for a frequency as well ascell specific re-selection parameters.

SystemInformationBlockType5 information element -- ASN1STARTSystemInformationBlockType5 ::= SEQUENCE { interFreqCarrierFreqListInterFreqCarrierFreqList, ..., lateNonCriticalExtension OCTET STRING(CONTAINING SystemInformationBlockType5-v8h0-IEs) OPTIONAL,[[ interFreqCarrierFreqList-v1250 InterFreqCarrierFreqList-v1250OPTIONAL, - - Need OR interFreqCarrierFreqListExt-r12InterFreqCarrierFreqListExt-r12 OPTIONAL - - Need OR ]],[[ interFreqCarrierFreqListExt-v1280 InterFreqCarrierFreqListExt-v1280OPTIONAL -- Need OR ]], [[ interFreqCarrierFreqList-v1310InterFreqCarrierFreqList-v1310 OPTIONAL, -- Need ORinterFreqCarrierFreqListExt-v1310 InterFreqCarrierFreqListExt-v1310OPTIONAL -- Need OR ]] } SystemInformationBlockType5-v8h0-IEs ::=SEQUENCE { interFreqCarrierFreqList-v8h0 SEQUENCE (SIZE (1..maxFreq)) OFInterFreqCarrierFreqInfo-v8h0  OPTIONAL, -- Need OP nonCriticalExtensionSystemInformationBlockType5-v9e0-IEs OPTIONAL }SystemInformationBlockType5-v9e0-IEs ::= SEQUENCE {interFreqCarrierFreqList-v9e0 SEQENCE (SIZE (1..maxFreq)) OFInterFreqCarrierFreqInfo-v9e0 OPTIONAL, -- Need OR nonCriticalExtensionSystemInformationBlockType5-v10j0-IEs OPTIONAL }SystemInformationBlockType5-v10j0-IEs ::= SEQUENCE {interFreqCarrierFreqList-v10j0 SEQUENCE (SIZE (1..maxFreq)) OFInterFreqCarrierFreqInfo-v10j0 OPTIONAL, -- Need OR nonCriticalExtensionSEQUENCE { } OPTIONAL } InterFreqCarrierFreqList ::= SEQUENCE (SIZE(1..maxFreq)) OF InterFreqCarrierFreqInfo InterFreqCarrierFreqList-v1250::= SEQUENCE (SIZE (1.. maxFreq)) OF  InterFreqCarrierFreqInfo-v1250InterFreqCarrierFreqListExt-r12 ::= SEQUENCE (SIZE (1.. maxFreq)) OF InterFreqCarrierFreqInfo-r12 InterFreqCarrierFreqListExt-v1280 ::=SEQUENCE (SIZE (1.. maxFreq)) OF  InterFreqCarrierFreqInfo-v10j0InterFreqCarrierFreqList-v1310 ::= SEQUENCE (SIZE (1.. maxFreq)) OF InterFreqCarrierFreqInfo-v1310 InterFreqCarrierFreqListExt-v1310 ::=SEQUENCE (SIZE (1.. maxFreq) OF  InterFreqCarrierFreqInfo-v1310InterFreqCarrierFreqInfo ::= SEQUENCE { dl-CarrierFreq ARFCN-ValueEUTRA,q-RxLevMin Q-RxLevMin, p-Max P-Max OPTIONAL, - - Need OPt-ReselectionEUTRA T-Reselection, t-ReselectionEUTRA-SFSpeedStateScaleFactors OPTIONAL, - - Need OP threshX-HighReselectionThreshold, threshX-Low ReselectionThreshold,allowedMeasBandwidth AllowedMeasBandwidth, presenceAntennaPort1PresenceAntennaPort1, cellReselectionPriority CellReselectionpriorityOPTIONAL, - - Need OP neighCellConfig NeighCellConfig, q-OffsetFreqQ-OffsetRange DEFAULT dB0, interFreqNeighCellList InterFreqNeighCellListOPTIONAL, - - Need OR interFreqBlackCellList InterFreqBlackCellListOPTIONAL, - - Need OR ..., [[ q-QualMin-r9 Q-QualMin-r9 OPTIONAL, - -Need OP threshX-Q-r9 SEQUENCE { threshX-HighQ-r9ReselectionThresholdQ-r9, threshX-LowQ-r9 ReselectionThresholdQ-r9 }OPTIONAL - - Cond RSRQ ]], [[ q-QualMinWB-r11 Q-QualMin-r9 OPTIONAL --Cond WB-RSRQ ]]

 - - 

 - - 

} InterFreqCarrierFreqInfo-v8h0 ::= SEQUENCE { multiBandInfoListMultiBandInfoList OPTIONAL -- Need OR } InterFreqCarrierFreqInfo-v9e0::= SEQUENCE { dl-CarrierFreq-v9e0 ARFCN-ValueEUTRA-v9e0 OPTIONAL, --Cond dl- FreqMax multiBandInfoList-v9e0 MultiBandInfoList-v9e0OPTIONAL, -- Need OR } InterFreqCarrierFreqInfo-v10j0 ::= SEQUENCE {freqBandInfo-r10 NS-PmaxList-r10  OPTIONAL, -- Need ORmultiBandInfoList-v10j0 MultiBandInfoList-v10j0 OPTIONAL -- Need OR }InterFreqCarrierFreqInfo-v1250 ::= SEQUENCE { reducedMeasPerformance-r12ENUMERATED {true} OPTIONAL, -- Need OP q-QualMinRSRQ-OnAllSymbols-r12Q-QualMin-r9 OPTIONAL -- Cond RSRQ2 } InterFreqCarrierFreqInfo-r12 ::=SEQUENCE { dl-CarrierFreq-r12 ARFCN-ValueEUTRA-r9, q-RxLevMin-r12Q-RxLevMin, p-Max-r12 P-Max OPTIONAL, - - Need OP t-ReselectionEUTRA-r12T-Reselection, t-ReselectionEUTRA-SF-r12 SpeedStateScaleFactorsOPTIONAL, - - Need OP threshX-High-r12 ReselectionThreshold,threshX-Low-r12 ReselectionThreshold, allowedMeasBandwidth-r12AllowedMeasBandwidth, presenceAntennaPort1-r12 PresenceAntennaPort1,cellReselectionPriority-r12 CellReselectionPriority OPTIONAL, - - NeedOP neighCellConfig-r12 NeighCellConfig, q-OffsetFreq-r12 Q-OffsetRangeDEFAULT dB0, interFreqNeighCellList-r12 InterFreqNeighCellListOPTIONAL, - - Need OR interFreqBlackCellList-r12 InterFreqBlackCellListOPTIONAL, - - Need OR q-QualMin-r12 Q-QualMin-r9 OPTIONAL, - - Need OPthreshX-Q-r12 SEQUENCE { threshX-HighQ-r12 ReselectionThresholdQ-r9,threshX-LowQ-r12 ReselectionThresholdQ-r9 } OPTIONAL, -- Cond RSRQq-QualMinWB-r12 Q-QualMin-r9 OPTIONAL, -- Cond WB-RSRQmultiBandInfoList-r12 MultiBandInfoList-r11 OPTIONAL, -- Need ORreducedMeasPerformance-r12 ENUMERATED {true} OPTIONAL, -- Need OPq-QualMinRSRQ-OnAllSymbols-r12 Q-QualMin-r9 OPTIONAL, -- Cond RSRQ2 ...} InterFreqCarrierFreqInfo-v1310 ::= SEQUENCE {cellReselectionSubPriority-r13 CellReselectionSubPriority-r13 OPTIONAL,-- Need OP redistributionInterFreqInfo-r13RedistributionInterFreqInfo-r13 OPTIONAL, -- Need OPcellSelectionInfoCE-r13 CellSelectionInfoCE-r13 OPTIONAL, -- Need OPt-ReselectionEUTRA-CE-r13 T-ReSelectionEUTRA-CE-r13 OPTIONAL -- Need OP} InterFreqNeighCellList ::= SEQUENCE (SIZE (1..maxCellInter)) OFInterFreqNeighCellInfo InterFreqNeighCellInfo ::= SEQUENCE { physCellIdPhysCellId, q-OffsetCell Q-OffsetRange } InterFreqBlackCellList ::=SEQUENCE (SIZE (1..maxCellBlack)) OF PhysCellIdRangeRedistributionInterFreqInfo-r13 ::= SEQUENCE {redistributionFactorFreq-r13 RedistributionFactor-r13 OPTIONAL, -- NeedOP redistributionNeighCellList-r13 RedistributionNeighCellList-r13OPTIONAL --Need OP } RedistributionNeighCellList-r13 ::= SEQUENCE (SIZE(1..maxCellInter)) OF RedistributionNeighCell-r13RedistributionNeighCell-r13 ::= SEQUENCE { physCellId-r13 PhysCellId,redistributionFactorCell-r13 RedistributionFactor-r13RedistributionFactor-r13 ::= INTEGER(1..10) -- ASN1STOP

SystemInformationBlockType5 field descriptions asyncNeighCells Indicateswhether the neighbor celts on the carrier frequency indicated bydl-Carrierfreq are unsynchronized with the PCell. If present, the UEperforms discovery signals measurement on the carrier frequencyindicated by dl-CarrierFreq according to the measDS-Config. If set totrue, and measDS-Config is not present, the UE performs discoverysignals measurement on the carrier frequency indicated by dl-CarrierFreqassuming any possible discovery signals timing, freqBandInfo A list ofadditionalPmax and additionalSpectrumEmission values as defined in TS36.101 [42, table 6.2.4-1] for the frequency band represented bydl-CarrierFreq for which cell reselection parameters are common.interFreqBlackCellList List of blacklisted inter-frequency neighbouringcells. interFreqCarrierFreqList List of neighbouring inter-frequencies.E-UTRAN does not configure more than one entry for the same physicalfrequency regardless of the E-ARFCN used to indicate this. If E-UTRANincludes interFreqCarrierFreqList-v8h0, interFreqCarrierFreqList-v9e0,InterFreqCarrierFreqList-v1250 and/or InterFreqCarrierFreqList-v1310, itincludes the same number of entries, and listed in the same order, as ininterFreqCarrierFreqList (i.e. without suffix). See Annex D for moredescriptions. interFreqCarrierFreqListExt List of additionalneighbouring inter-frequencies, i.e. extending the size of theinter-frequency carrier list using the general principles specified in5.1.2. E-UTRAN does not configure more than one entry for the samephysical frequency regardless of the E-ARFCN used to indicate this.EUTRAN may include interFreqCarrierFreqListExt even ifinterFreqCarrierFreqList (i.e without suffix) does not include maxFreqentries. If E-UTRAN includes InterFreqCarrierFreqListExt-v1310 itincludes the same number of entries, and listed in the same order, as ininterFreqCarrierFreqListExt-r12. interFreqNeighCellList List ofinter-frequency neighbouring cells with specific cell re-selectionparameters. multiBandInfoList Indicates the list of frequency bands inaddition to the band represented by dl-CarrierFreq for which cellreselection parameters are common. E-UTRAN indicates at mostmaxMultiBands frequency bands (i.e. the total number of entries acrossboth multiBandInfoList and multiBandInfoList-v9e0 is below this limit).multiBandInfoList-v10j0 A list of additionalPmax andadditionalSpectrumEmission values as defined in TS 36.101 [42, table6.2.4-1] for the frequency bands in multiBandInfoList (i.e. withoutsuffix) and multiBandInfoList-v9e0. If E-UTRAN includesmultiBandInfoList-v10j0, it includes the same number of entries, andlisted in the same order, as in multiBandInfoList (i.e. without suffix).neighCellDMTC-Config Parameters applicable to discovery signalsmeasurement on the carrier frequency indicated by dl- CarrierFreq. p-MaxValue applicable for the neighbouring E-UTRA cells on this carrierfrequency. If absent the UE applies the maximum power according to theUE capability. q-OffsetCell Parameter “Qoffset_(s, n)” in TS 36.304 [4].q-OffsetFreq Parameter “Qoffset_(frequency)” in TS 36.304 [4]. q-QualMinParameter “Q_(qualmin)” in TS 36.304 [4]. If the field is not present,the UE applies the (default) value of negative infinity for Q_(qualmin).NOTE 1. q-QualMinRSRQ-OnAllSymbols If this field is present andsupported by the UE, the UE shall, when performing RSRQ measurements,perform RSRQ measurement on all OFDM symbols in accordance with TS36.214 [48]. NOTE 1. q-QualMinWB If this field is present and supportedby the UE, the UE shall, when performing RSRQ measurements, use a widerbandwidth in accordance with TS 36.133 [16]. NOTE 1.redistributionFactorFreq Parameter redistributionFactorFreq in TS 36.304[4]. redistributionFactorCell Parameter redistributionFactorCell in TS36.304 [4]. reducedMeasPerformance Value TRUE indicates that theneighbouring inter-frequency is configured for reduced measurementperformance, see TS 36.133 [16]. If the field is not included, theneighbouring inter-frequency is configured for normal measurementperformance, see TS 36.133 [16]. threshX-High Parameter“Thresh_(X, HighP)” in TS 36.304 [4]. threshX-HighQ Parameter“Thresh_(X, HighQ)” in TS 36.304 [4]. threshX-Low Parameter“Thresh_(X, LowP)” in TS 36.304 [4]. threshX-LowQ Parameter“Thresh_(X, LowQ)” in TS 36.304 [4]. t-ReselectionEUTRA Parameter“Treselection_(EUTRA)” in TS 36.304 [4]. t-ReselectionEUTRA-SF Parameter“Speed dependent ScalingFactor for Treselection_(EUTRA)” in TS 36.304[4]. If the field is not present, the UE behaviour is specified in TS36.304 [4].

FIG. 11 illustrates the operation of the radio access node 14 and thewireless device 12 according to some embodiments of the presentdisclosure in which a DMTC is provided to the wireless device 12 for acarrier frequency together with a respective async indication within ameasurement object used to configure the wireless device 12 to performmeasurements on the carrier frequency. As illustrated, the radio accessnode 14 sends a measurement object to the wireless device 12 where themeasurement object includes: (a) an async indication for a respectivecarrier frequency and (b) a DMTC for the carrier frequency to be used ifthe async indication for the downlink carrier frequency is set to avalue that indicates that one or more asynchronous cells are operatingon the downlink carrier frequency (i.e., indicates that there areasynchronous cell(s) on the downlink carrier frequency) (step 300). Thewireless device 12 utilizes the DMTC for the carrier frequency (step302). The wireless device 12 may use the DMTC to perform measurementssuch as RRM measurements on the asynchronous cells on the carrierfrequency indicated in the measurement object.

Below, an example of a measurement object, namely MeasObjectEUTRA,including the async indication and DMTC configuration for a specifiedcarrier frequency are provided below. Note that, as discussed above, themeasurement object may be further modified to include a separate DMTCconfiguration for synchronous cells on the specified carrier frequencyand, in some embodiments, a sync indication that, if set, indicates thatthere are synchronous cells on the specified carrier frequency (and thusthat the wireless device 12 should use the DMTC provided for synchronouscells when performing measurements on the specified carrier frequency).In the example below, portions related to DMTC and async indication arebolded and italicized.

The IE MeasObjectEUTRA specifies information applicable forintra-frequency or inter-frequency E-UTRA cells.

MeasObjectEUTRA information element -- ASN1START MeasObjectEUTRA ::=SEQUENCE { carrierFreq ARFCN-ValueEUTRA, allowedMeasBandwidthAllowedMeasBandwidth, presenceAntennaPort1 PresenceAntennaPort1,neighCellConfig NeighCellConfig, offsetFreq Q-OffsetRange DEFAULT dB0,-- Cell list cellsToRemoveList CellIndexList OPTIONAL, -- Need ONcellsToAddModList CellsToAddModList OPTIONAL, -- Need ON -- Black listblackCellsToRemoveList CellIndexList OPTIONAL, -- Need ONblackCellsToAddModList BlackCellsToAddModList OPTIONAL, -- Need ONcellForWhichToReportCGI PhysCellId OPTIONAL, -- Need ON ...,[[measCycleSCell-r10 MeasCycleSCell-r10 OPTIONAL, -- Need ONmeasSubframePatternConfigNeigh-r10MeasSubframePatternConfigNeigh-r10 OPTIONAL ]], [[widebandRSRQ-Meas-r11BOOLEAN OPTIONAL -- Cond WB-RSRQ ]], [[ altTTT-CellsToRemoveList-r12CellIndexList OPTIONAL, -- Need ON altTTT-CellsToAddModList-r12AltTTT-CellsToAddModList-r12 OPTIONAL, - - Need ON t312-r12 CHOICE {release NULL, setup ENUMERATED {ms0, ms50, ms100, ms200, ms300, ms400,ms500, ms1000} } OPTIONAL, -- Need ON reducedMeasPerformance-r12 BOOLEANOPTIONAL, -- Need ON measDS-Config-r12 MeasDS-Config-r12 OPTIONAL --Need ON ]], [[ whiteCellsToRemoveList-r13 CellIndexList OPTIONAL, --Need ON whiteCellsToAddModList-r13 WhiteCellsToAddModList-r13OPTIONAL, -- Need ON rmtc-Config-r13 RMTC-Config-r13 OPTIONAL, -- NeedON carrierFreq-r13 ARFCN-ValueEUTRA-v9e0 OPTIONAL - - Need ON ]],

 --

 --

} MeasObjectEUTRA-v9e0 ::= SEQUENCE { carrierFreq-v9e0ARFCN-ValueEUTRA-v9e0 } CellsToAddModList ::= SEQUENCE (SIZE(1..maxCellMeas)) OF CellsToAddMod CellsToAddMod ::= SEQUENCE {cellIndex INTEGER (1..maxCellMeas), physCellId PhysCellId,cellIndividualOffset Q-OffsetRange } BlackCellsToAddModList ::= SEQUENCE(SIZE (1..maxCellMeas)) OF BlackCellsToAddMod BlackCellsToAddMod ::=SEQUENCE { cellIndex INTEGER (1..maxCellMeas), physCellIdRangePhysCellIdRange } MeasCycleSCell-r10 ::= ENUMERATED {sf160, sf256,sf320, sf512, sf640, sf1024, sf1280, spare1}MeasSubframePatternConfigNeigh-r10 ::= CHOICE { release NULL, setupSEQUENCE { measSubframePatternNeigh-r10 MeasSubframePattern-r10,measSubframeCellList-r10 MeasSubframeCellList-r10 OPTIONAL - - Condalways } } MeasSubframeCellList-r10 ::= SEQUENCE (SIZE (1..maxCellMeas))OF PhysCellIdRange AltTTT-CellsToAddModList-r12 ::= SEQUENCE (SIZE(1..maxCellMeas)) OF AltTTT- CellsToAddMod-r12 AltTTT-CellsToAddMod-r12::= SEQUENCE { cellIndex-r12 INTEGER (1..maxCellMeas),physCellIdRange-r12 PhysCellIdRange } WhiteCellsToAddModList-r13 ::=SEQUENCE (SIZE (1..maxCellMeas)) OF WhiteCellsToAddMod-r13WhiteCellsToAddMod-r13 ::= SEQUENCE { cellIndex-r13 INTEGER(1..maxCellMeas), physCellIdRange-r13 PhysCellIdRange } RMTC-Config-r13::= CHOICE { release NULL, setup SEQUENCE { rmtc-Period-r13 ENUMERATED{ms40, ms80, ms160, ms320, ms640}, rmtc-SubframeOffset-r13INTEGER(0..639) OPTIONAL, - - Need ON measDuration-r13 ENUMERATED {sym1,sym14, sym28, sym42, sym70}, ... } } -- ASN1STOP

MeasObjectEUTRA field descriptions altTTT-CellsToAddModList List ofcells to add/modify in the cell list for which the alternative time totrigger specified by alternativeTimeToTrigger in reportConfigEUTRA, ifconfigured, applies. altTTT-CellsToRemoveList List of cells to removefrom the list of cells for alternative time to trigger. asyncNeighCellsIndicates whether the neighbor cells on the carrier frequency indicatedby carrierFreq are unsynchronized with the PCell. If present, the UEshall perform discovery signals measurement on the carrier frequencyindicated by carrierFreq according to the measDS-Config. If set to true,and measDS-Config is not present, the UE shall perform discovery signalsmeasurement on the carrier frequency indicated by carrierFreq assumingany possible discovery signals timing, blackCellsToAddModList List ofcells to add/modify in the black list of cells. blackCellsToRemoveListList of cells to remove from the black list of cells. carrierFreqIdentifies E-UTRA carrier frequency for which this configuration isvalid. E-UTRAN does not configure more than one measurement object forthe same physical frequency regardless of the E-ARFCN used to indicatethis. CarrierFreq-r13 is included only when the extension listmeasObjectToAddModListExt-r13 is used. If carrierFreq-r13 is present,carrierFreq (i.e., without suffix) shall be set to value maxEARFCN.cellIndex Entry index in the cell list. An entry may concern a range ofcells, in which case this value applies to the entire range.cellIndividualOffset Cell individual offset applicable to a specificcell. Value dB −24 corresponds to −24 dB, dB −22 corresponds to −22 dBand so on. cellsToAddModList List of cells to add/modify in the celllist. cellsToRemoveList List of cells to remove from the cell list.measCycleSCell The parameter is used only when an SCell is configured onthe frequency indicated by the measObject and is in deactivated state,see TS 36.133 [16, 8.3.3]. E-UTRAN configures the parameter whenever anSCell is configured on the frequency indicated by the measObject, butthe field may also be signalled when an SCell is not configured. Valuesf160 corresponds to 160 sub-frames, sf256 corresponds to 256 sub-framesand so on. measDS-Config Parameters applicable to discovery signalsmeasurement on the carrier frequency indicated by carrierFreq.measDuration Number of consecutive symbols for which the Physical Layerreports samples of RSSI, see TS 36.214 [48]. Value sym1 corresponds toone symbol, sym14 corresponds to 14 symbols, and so on.measSubframeCellList List of cells for which measSubframePatternNeigh isapplied. measSubframePatternNeigh Time domain measurement resourcerestriction pattern applicable to neighbour cell RSRP and RSRQmeasurements on the carrier frequency indicated by carrierFreq. Forcells in measSubframeCellList the UE shall assume that the subframesindicated by measSubframePatternNeigh are non-MBSFN subframes, and havethe same special subframe configuration as PCell. offsetFreq Offsetvalue applicable to the carrier frequency. Value dB −24 corresponds to−24 dB, dB −22 corresponds to −22 dB and so on. physCellId Physical cellidentity of a cell in the cell list. physCellIdRange Physical cellidentity or a range of physical cell identities. reducedMeasPerformanceIf set to TRUE, the EUTRA carrier frequency is configured for reducedmeasurement performance, otherwise it is configured for normalmeasurement performance, see TS 36.133 [16]. rmtc-Config Parametersapplicable to RSSI and channel occupancy measurement on the carrierfrequency indicated by carrierFreq. rmtc-Period Indicates the RSSImeasurement timing configuration (RMTC) periodicity for this frequency.Value ms 40 corresponds to 40 ms periodicity, ms 80 corresponds to 80 msperiodicity and so on, see TS 36.214 [48]. rmtc-SubframeOffset Indicatesthe RSSI measurement timing configuration (RMTC) subframe offset forthis frequency. The value of rmtc-SubframeOffset should be smaller thanthe value of rmtc-Period, see TS 36.214 [48]. For inter- frequencymeasurements, this field is optional present and if it is notconfigured, the UE chooses a random value as rmtc-SubframeOffset formeasDuration which shall be selected to be between 0 and the configuredrmtc-Period with equal probability. t312 The value of timer T312. Valuems 0 represents 0 ms, ms 50 represents 50 ms and so on.widebandRSRQ-Meas If this field is set to TRUE, the UE shall, whenperforming RSRQ measurements, use a wider bandwidth in accordance withTS 36.133 [16]. whiteCellsToAddModList List of cells to add/modify inthe white list of cells. whiteCellsToRemoveList List of cells to removefrom the white list of cells.

Below is an example of MeasDS-Config which is used in the examplesabove. The IE MeasDS-Config specifies information applicable fordiscovery signals measurement.

MeasDS-Config information elements -- ASN1START MeasDS-Config-r12 ::=CHOICE { release NULL, setup SEQUENCE { dmtc-PeriodOffset-r12 CHOICE {ms40-r12 INTEGER(0..39), ms80-r12 INTEGER(0..79), ms160-r12INTEGER(0..159), ... }, ds-OccasionDuration-r12 CHOICE { durationFDD-r12INTEGER(1..maxDS-Duration-r12), durationTDD-r12INTEGER(2..maxDS-Duration-r12) }, measCSI-RS-ToRemoveList-r12MeasCSI-RS-ToRemoveList-r12 OPTIONAL, -- Need ONmeasCSI-RS-ToAddModList-r12 MeasCSI-RS-ToAddModList-r12 OPTIONAL, --Need ON ... } } MeasDS-Config-MF ::= CHOICE { release NULL, setupSEQUENCE { dmtc-Period-MF ENUMERATED {ms40, ms80, ms160}, dmtc-Offet-MFINTEGER(0..159), dmtc-Duration-MF INTEGER(1..10),measCSI-RS-ToRemoveList-MF MeasCSI-RS-ToRemoveList-r12 OPTIONAL, -- NeedON measCSI-RS-ToAddModList-MF MeasCSI-RS-ToAddModList-r12 OPTIONAL, --Need ON ... } } MeasCSI-RS-ToRemoveList-r12 ::= SEQUENCE (SIZE(1..maxCSI-RS-Meas-r12)) OF MeasCSI-RS-Id- r12MeasCSI-RS-ToAddModList-r12 ::= SEQUENCE (SIZE (1..maxCSI-RS-Meas-r12))OF MeasCSI-RS- Config-r12 MeasCSI-RS-Id-r12 ::= INTEGER(1..maxCSI-RS-Meas-r12) MeasCSI-RS-Config-r12 ::= SEQUENCE {measCSI-RS-Id-r12 MeasCSI-RS-Id-r12, physCellId-r12 INTEGER (0..503),scramblingIdentity-r12 INTEGER (0..503), resourceConfig-r12 INTEGER(0..31), subframeOffset-r12 INTEGER (0..4), csi-RS-IndividualOffset-r12Q-OffsetRange, ... } -- ASN1STOP

MeasDS-Config field descriptions csi-RS-IndividualOffset CSI-RSindividual offset applicable to a specific CSI-RS resource. Value dB −24corresponds to −24 dB, dB −22 corresponds to −22 dB and so on.dmtc-Duration Indicates the duration in number of subframes during whichthe UE shall expect discovery signals. dmtc-Period Indicates thediscovery signals measurement timing configuration (DMTC) periodicity(dmtc-Periodicity). Value ms 40 corresponds to 40 ms, ms 80 correspondsto 80 ms and so on. dmtc-Offset Indicates the discovery signalsmeasurement timing configuration (DMTC) offset (dmtc-Offset). The valueof DMTC offset is in number of subframe(s). dmtc-PeriodOffset Indicatesthe discovery signals measurement timing configuration (DMTC)periodicity (dmtc-Periodicity) and offset (dmtc-Offset) for thisfrequency. For DMTC periodicity, value ms 40 corresponds to 40 ms, ms 80corresponds to 80 ms and so on. The value of DMTC offset is in number ofsubframe(s). The duration of a DMTC occasion is 6 ms.ds-OccasionDuration Indicates the duration of discovery signal occasionfor this frequency. Discovery signal occasion duration is common for allcells transmitting discovery signals on one frequency. The UE shallignore the field ds- OccasionDuration for a carrier frequency with aconfigured LAA SCell and apply a value 1 instead.measCSI-RS-ToAddModList List of CSI-RS resources to add/modify in theCSI-RS resource list for discovery signals measurement.measCSI-RS-ToRemoveList List of CSI-RS resources to remove from theCSI-RS resource list for discovery signals measurement. physCellIdIndicates the physical cell identity where UE may assume that the CSI-RSand the PSS/SSS/CRS corresponding to the indicated physical cellidentity are quasi co-located with respect to average delay and dopplershift. resourceConfig Parameter: CSI reference signal configuration, seeTS 36.211 [21, table 6.10.5.2-1 and 6.10.5.2-2]. For a carrier frequencywith a configured LAA SCell, E-UTRAN does not configure the values {0,4, 5, 9, 10, 11, 18, 19}. scramblingIdentity Parameter: Pseudo-randomsequence generator parameter, n_(ID), see TS 36.213 [23, 7.2.5].subframeOffset Indicates the subframe offset between SSS of the cellindicated by physCellId and the CSI-RS resource in a discovery signaloccasion. The field subframeOffset is set to values 0 for a carrierfrequency with a configured LAA SCell.

In some embodiments, the wireless device 12 sets up the DMTC inaccordance with the received dmtc-PeriodOffset or dmtc-Period-MF anddmtc-Offset-MF, respectively, i.e., the first subframe of each DMTCoccasion occurs at a System Frame Number (SFN) and subframe of the PCellmeeting the following condition:

SFN mod T=FLOOR(dmtc-Offset/10);

subframe=dmtc-Offset mod 10;

with T=dmtc-Periodicity/10;

On the concerned frequency, the wireless device 12 considers DRStransmission in subframes outside the DMTC occasion.

In certain embodiments according to option 3, as illustrated in FIG. 12,a method in an eNB (e.g., a method in a radio access node 14) comprisesdetermining whether to configure a SCell (step 400); in response todetermining to configure the SCell, determining whether the asyncindication is provided for the corresponding frequency (step 402); andin response to determining that the async indication is provided for thecorresponding frequency, sending the SCell's DMTC configuration in theSCell addition (step 404). The SCell addition may be provided via anRRCConnectionReconfiguration message, as described above.

Thus, in some embodiments, a method in a radio access node 14 forinforming a wireless communication device 12 about the discovery signaltiming, during which a wireless communication device is required tosearch for SCell discovery signals apart from the timing received viasystem information for other network nodes, comprises: determining aSCell for configuration; determining whether the neighbor cells on theSCell frequency are asynchronous; and indicating to the device the exactDMTC for the SCell via dedicated signaling.

In certain embodiments according to option 3, as illustrated in FIG. 13,a method in a UE (e.g., the wireless device 12) comprises determiningwhether the SCell addition includes DMTC configuration for the SCell(step 500); in response to determining that the SCell addition includesDMTC configuration for the SCell, (a) prioritizing measurementsaccording to the DMTC configuration provided via dedicated signaling forSCell measurements (step 502); and (b) if the async bit is set to avalue that indicates that one or more asynchronous cells are operatingon the frequency (step 504; YES), performing best effort measurements onthe neighbor cells on the frequency where the SCell has been added (step506). The method may use inter-frequency DMTC provided via systeminformation to minimize its battery consumption during RRM measurements.The inter-frequency DMTC may be provided on SIB5, for example. Note thatthe UE may prioritize measurements by, for example, performing thosemeasurements more frequently. Another example could be that, if the UEcan only process a limited number of cells, the UE prioritizes the cellsfound in the prioritized DMTC. Further note that performing best effortmeasurements means that there are no requirements for how quickly the UEneeds to find a report these cells and that it can choose not to searchto, e.g., save battery.

Thus, in some embodiments, a method in a wireless communication device12 comprises: determining whether the DMTC configuration is present inthe SCell addition; configuring and prioritizing the DMTC for discoverysignal measurements for the SCell; performing measurements for theSCell; and attempting to detect the discovery signals from neighborcells on the SCell frequency and performing measurements on neighborcells on the SCell frequency when possible.

As illustrated in FIG. 14, the method may further comprise, if the SCellconfiguration is removed (step 600, YES), deleting (i.e., removing) theDMTC configuration for the SCell (step 602) and performing discoverysignal measurements according to the DMTC configuration in, e.g., SIB5(step 604).

Although wireless communication devices 12 may represent communicationdevices that include any suitable combination of hardware and/orsoftware, these wireless communication devices may, in certainembodiments, represent devices such as an example wireless communicationdevice 12 illustrated in greater detail by FIGS. 15 and 16. Similarly,although the illustrated radio access node 14 may represent networknodes that include any suitable combination of hardware and/or software,these nodes may, in particular embodiments, represent devices such asthe example radio access node 14 illustrated in greater detail by FIGS.17 through 19.

Referring to FIG. 15, the wireless communication device 12 comprises aprocessor 20 (e.g., a Central Processing Unit(s) (CPU(s)), ApplicationSpecific Integrated Circuit(s) (ASIC(s)), Field Programmable GateArray(s) (FPGA(s)), and/or the like), a memory 22, a transceiver 24, andan antenna 26. In certain embodiments, some or all of the functionalitydescribed as being provided by UEs, MTC or M2M devices, and/or any othertypes of wireless communication devices may be provided by the processor20 executing instructions stored on a computer readable medium, such asthe memory 22 shown in FIG. 15. Alternative embodiments may includeadditional components beyond those shown in FIG. 15 that may beresponsible for providing certain aspects of the wireless communicationdevice's functionality, including any of the functionality describedherein.

FIG. 16 illustrates the wireless communication device 12 according tosome other embodiments of the present disclosure. As illustrated, thewireless communication device 12 includes one or more modules 28, eachof which is implemented in software. The module(s) 28 operate to performthe functions of the wireless communication device 12 (e.g., UE, M2M UE,MTC UE, or the like) described herein. For example, the module(s) 28 mayinclude a receiving module operable to receive a DMTC configuration asdescribed herein and a utilizing module operable to utilize the DMTCconfiguration as described herein.

Referring to FIG. 17, a radio access node 14 comprises a node processor32 (e.g., a CPU(s), ASIC(s), FPGA(s), and/or the like), a memory 34, anetwork interface 36, a transceiver 38, and an antenna 40. Asillustrated, together, the processor 32, the memory 34, and the networkinterface 36 are referred to as a control system 30. In certainembodiments, some or all of the functionality described as beingprovided by a base station, a node B, an eNB, and/or any other type ofnetwork node may be provided by the node processor 32 executinginstructions stored on a computer readable medium, such as the memory 34shown in FIG. 17. Alternative embodiments of the radio access node 14may comprise additional components to provide additional functionality,such as the functionality described herein and/or related supportingfunctionality.

FIG. 18 is a schematic block diagram that illustrates a virtualizedembodiment of the radio access node 14 according to some embodiments ofthe present disclosure. This discussion is equally applicable to othertypes of network nodes. Further, other types of network nodes may havesimilar virtualized architectures.

As used herein, a “virtualized” radio access node 14 is animplementation of the radio access node 14 in which at least a portionof the functionality of the radio access node 14 is implemented as avirtual component(s) (e.g., via a virtual machine(s) executing on aphysical processing node(s) in a network(s)). As illustrated, in thisexample, the radio access node 14 includes the control system 30 thatincludes the processor(s) 32 (e.g., CPUs, ASICs, FPGAs, and/or thelike), the memory 34, and the network interface 36. The radio accessnode 14 also includes the transceiver 38 coupled to the antenna(s) 40.The control system 30 is connected to the transceiver 38 via, forexample, an optical cable or the like. Alternatively, the control system30, the transceiver 38, and the antennas 40 may, e.g., be integratedinto a single unit. The control system 30 is connected to one or moreprocessing nodes 42 coupled to or included as part of a network(s) 44via the network interface 36. Each processing node 42 includes one ormore processors 46 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory48, and a network interface 50.

In this example, functions 52 of the radio access node 14 (e.g.,functions of the eNB or base station) described herein are implementedat the one or more processing nodes 42 or distributed across the controlsystem 30 and the one or more processing nodes 42 in any desired manner.In some particular embodiments, some or all of the functions 52 of theradio access node 14 described herein are implemented as virtualcomponents executed by one or more virtual machines implemented in avirtual environment(s) hosted by the processing node(s) 42. As will beappreciated by one of ordinary skill in the art, additional signaling orcommunication between the processing node(s) 42 and the control system30 is used in order to carry out at least some of the desired functions52. Notably, in some embodiments, the control system 30 may not beincluded, in which case the transceiver 38 communicates directly withthe processing node(s) 42 via an appropriate network interface(s).

FIG. 19 illustrates the radio access node 14 according to some otherembodiments of the present disclosure. As illustrated, the radio accessnode 14 includes one or more modules 54, each of which is implemented insoftware. The module(s) 54 operate to perform the functions of the radioaccess node 14 (e.g., eNB or base station) described herein. Forexample, the module(s) 54 may include a sending module operable totransmit a DMTC configuration as described herein.

The following acronyms are used throughout this disclosure.

-   -   μs Microsecond    -   3GPP Third Generation Partnership Project    -   AP Access Point    -   ASIC Application Specific Integrated Circuit    -   CA Carrier Aggregation    -   CC Component Carrier    -   CCA Clear Channel Assessment    -   CFI Control Format Indicator    -   CIF Carrier Indicator Field    -   CPU Central Processing Unit    -   CRS Cell-Specific Reference Symbol    -   CSI-RS Channel State Information Reference Signal    -   CSMA/CA Carrier Sense Multiple Access with Collision Avoidance    -   DCI Downlink Control Information    -   DFT Discrete Fourier Transform    -   DMTC Discovery Signal Measurement Timing Configuration    -   DRS Discovery Reference Signal    -   DwPTS Downlink Part of the Special Subframe    -   eNB Enhanced or Evolved Node B    -   ePDCCH Enhanced Physical Downlink Control Channel    -   eSIB Enhanced System Information Block    -   E-UTRA Evolved Universal Terrestrial Radio Access    -   FDD Frequency Division Duplexing    -   FDMA Frequency Division Multiple Access    -   FPGA Field Programmable Gate Array    -   GHz Gigahertz    -   HARQ Hybrid Automatic Repeat Request    -   ID Identity    -   IE Information Element    -   LA License Assisted    -   LAA License Assisted Access    -   LBT Listen-Before-Talk    -   LTE Long Term Evolution    -   LTE-U Long Term Evolution in the Unlicensed Band    -   M2M Machine-to-Machine    -   MAC Medium Access Control    -   MHz Megahertz    -   ms Millisecond    -   MTC Machine Type Communication    -   NAS Non-Access Stratum    -   OFDM Orthogonal Frequency Division Multiplexing    -   PCell Primary Cell    -   PCFICH Physical Control Format Indicator Channel    -   PCID Physical Cell Identity    -   PDCCH Physical Downlink Control Channel    -   PDSCH Physical Downlink Shared Channel    -   PSS Primary Synchronization Signal    -   PUCCH Physical Uplink Control Channel    -   PUSCH Physical Uplink Shared Channel    -   RAT Radio Access Technology    -   Rel Release    -   RRC Radio Resource Control    -   RRM Radio Resource Management    -   RSRP Reference Signal Received Power    -   RSRQ Reference Signal Received Quality    -   RSSI Received Signal Strength Indicator    -   SCell Secondary Cell    -   SC-FDMA Single Carrier Frequency Division Multiple Access    -   SFN System Frame Number    -   SIB System Information Block    -   SIB-MF MulteFire System Information Block    -   SSS Secondary Synchronization Signal    -   TDD Time Division Duplexing    -   TS Technical Specification    -   UE User Equipment    -   VCID Virtual Cell Identity    -   WLAN Wireless Local Area Network

Those skilled in the art will recognize improvements and modificationsto the embodiments of the present disclosure. All such improvements andmodifications are considered within the scope of the concepts disclosedherein and the claims that follow.

1. A method of operation of a radio access node in a cellularcommunications network, comprising: sending, to a wireless device, aDiscovery Signal Measurement Timing Configuration, DMTC, for a frequencyon which one or more asynchronous cells are operating, an asynchronouscell being a cell that is unsynchronized with a primary cell of thewireless device; wherein sending the DMTC comprises transmitting systeminformation or a measurement object comprising: an indication of whetherone or more asynchronous cells are operating on the frequency; and theDMTC for the frequency to be used by the wireless device if theindication is set to a value that indicates that one or moreasynchronous cells are operating on the frequency. 2-5. (canceled) 6.The method of claim 1 wherein transmitting the system information or themeasurement object comprises transmitting the system informationcomprising: the indication of whether one or more asynchronous cells areoperating on the frequency, wherein the one or more asynchronous cellsare one or more intra-frequency asynchronous cells; and the DMTC for thefrequency to be used by the wireless device if the indication is set toa value that indicates that one or more intra-frequency asynchronouscells are operating on the frequency.
 7. The method of claim 6 whereinthe DMTC comprises at least one of a DMTC periodicity, a DMTC offset,and a DMTC duration.
 8. The method of claim 6 wherein the systeminformation is a System Information Block type 3, SIB3, informationelement.
 9. The method of claim 1 wherein transmitting the systeminformation or the measurement object comprises transmitting the systeminformation comprising: the indication of whether one or moreasynchronous cells are operating on the frequency, wherein the one ormore asynchronous cells are one or more inter-frequency asynchronouscells; and the DMTC for the frequency to be used by the wireless deviceif the indication is set to a value that indicates that one or moreinter-frequency asynchronous cells are operating on the frequency. 10.(canceled)
 11. The method of claim 1 wherein transmitting the systeminformation or the measurement object comprises transmitting themeasurement object to the wireless device, the measurement objectcomprising: the indication of whether one or more asynchronous cells areoperating on the frequency; and the DMTC for the frequency to be used bythe wireless device if the indication is set to a value that indicatesthat one or more asynchronous cells are operating on the frequency. 12.The method of claim 1 wherein sending the DMTC comprises sending theDMTC and a second DMTC, the DMTC and the second DMTC being separateDMTCs and one of the DMTCs is associated with an asynchronous indicationand the other DMTC is associated with a synchronous indication.
 13. Themethod of claim 1 wherein the DMTC is a DMTC for the frequency on whichone or more asynchronous cells are operating, and sending the DMTCcomprises sending the DMTC together with an asynchronous indication thatindicates whether any asynchronous cells are operating on the frequencyand a second DMTC for the frequency together with an indication ofwhether any synchronous cells are operating on the frequency. 14-15.(canceled)
 16. A radio access node for a cellular communicationsnetwork, comprising: a processor; and memory comprising instructionsexecutable by the processor whereby the radio access node is operableto: send, to a wireless device, a Discovery Signal Measurement TimingConfiguration, DMTC, for a frequency on which one or more asynchronouscells are operating, an asynchronous cell being a cell that isunsynchronized with a primary cell of the wireless device; wherein, inorder to send the DMTC, the radio access node is operable to transmitsystem information or a measurement object comprising: an indication ofwhether one or more asynchronous cells are operating on the frequency;and the DMTC for the frequency to be used by the wireless device if theindication is set to a value that indicates that one or moreasynchronous cells are operating on the frequency. 17-19. (canceled) 20.A method of operation of a wireless device in a cellular communicationsnetwork, comprising: receiving a Discovery Signal Measurement TimingConfiguration, DMTC, for a frequency on which one or more asynchronouscells are operating, the one or more asynchronous cells being one ormore cells that are unsynchronized with a primary cell of the wirelessdevice, wherein receiving the DMTC comprises receiving systeminformation or a measurement object comprising: an indication of whetherone or more asynchronous cells are operating on the frequency and theDMTC for the frequency to be used by the wireless device if theindication is set to a value that indicates that one or moreasynchronous cells are operating on the frequency; and utilizing theDMTC. 21-24. (canceled)
 25. The method of claim 20 wherein receiving thesystem information or the measurement object comprises receiving thesystem information comprising: the indication of whether one or moreasynchronous cells are operating on the frequency, wherein the one ormore asynchronous cells are one or more intra-frequency asynchronouscells; and the DMTC for the frequency to be used by the wireless deviceif the indication is set to a value that indicates that one or moreintra-frequency asynchronous cells are operating on the frequency. 26.The method of claim 25 wherein the system information is a SystemInformation Block type 3 (SIB3) information element.
 27. The method ofclaim 20 wherein receiving the system information or the measurementobject comprises receiving the system information comprising: theindication of whether one or more asynchronous cells are operating onthe frequency, wherein the one or more asynchronous cells are one ormore inter-frequency asynchronous cells; and the DMTC for the frequencyto be used by the wireless device if the indication is set to a valuethat indicates that one or more inter-frequency asynchronous cells areoperating on the frequency.
 28. The method of claim 27 wherein thesystem information is a System Information Block type 5 (SIB5)information element.
 29. The method of claim 20 wherein receiving thesystem information or the measurement object comprises receiving themeasurement object, the measurement object comprising: the indication ofwhether one or more asynchronous cells are operating on the frequency;and the DMTC for the frequency to be used by the wireless device if theindication is set to a value that indicates that one or moreasynchronous cells are operating on the frequency.
 30. The method ofclaim 20 wherein receiving the DMTC comprises receiving the DMTC and asecond DMTC, the DMTC and the second DMTC being separate DMTCs and oneof the DMTCs is associated with an asynchronous indication and the otherDMTC is associated with a synchronous indication.
 31. The method ofclaim 20 wherein the DMTC is a DMTC for the frequency on which one ormore asynchronous cells are operating, and receiving the DMTC comprisesreceiving the DMTC together with an asynchronous indication thatindicates whether any asynchronous cells are operating on the frequencyand a second DMTC for the frequency together with an indication ofwhether any synchronous cells are operating on the frequency. 32-33.(canceled)
 34. A wireless device for a cellular communications network,comprising: a transceiver; a processor; and memory comprisinginstructions executable by the processor whereby the wireless device isoperable to: receive a Discovery Signal Measurement TimingConfiguration, DMTC, for a frequency on which one or more asynchronouscells are operating, the one or more asynchronous cells being one ormore cells that are unsynchronized with a primary cell of the wirelessdevice wherein, in order to receive the DMTC, the wireless device isoperable to receive system information or a measurement objectcomprising: an indication of whether one or more asynchronous cells areoperating on the frequency and the DMTC for the frequency to be used bythe wireless device if the indication is set to a value that indicatesthat one or more asynchronous cells are operating on the frequency; andutilize the DMTC. 35-37. (canceled)